Category: basics Of Computer Science

Discuss Basics of Computer Science ”; Previous Next Computer Science is one of the disciplines of modern science under which, we study about the various aspects of computer technologies, their development, and their applications in the present world. Likewise, Computer Science includes a wide range of topics such as the development of Computer Technology (hardware and software), application of Computer technology in today’s life, information technology, computer threat, computer security, etc. However, we have segregated this tutorial into different chapters for easy understanding. Print Page Previous Next Advertisements ”;

Basics of Computer Science – Threat ”; Previous Next Threat in a computer system is a possible danger that might put your data security on stake. The damage is at times irreparable. Definition As defined by the National Information Assurance Glossary − “Any circumstance or event with the potential to adversely impact an IS through unauthorized access, destruction, disclosure, modification of data, and/or denial of service.” A computer threat can be “intentional” such as hacking or “accidental” such as malfunctioning of or physical damage. Types of Threat Following are the most common types of computer threats − Physical damage − It includes fire, water, pollution, etc. Natural events − It includes climatic, earthquake, volcanic activity, etc. Loss of services − It includes electrical power, air conditioning, telecommunication, etc. Technical failures − It includes problems in equipment, software, capacity saturation, etc. Deliberate type − It includes spying, illegal processing of data, etc. Some other threats include error in use, abuse of rights, denial of actions, eavesdropping, theft of media, retrieval of discarded materials, etc. Sources of Threat The possible sources of a computer threat may be − Internal − It includes employees, partners, contractors (and vendors). External − It includes cyber-criminals (professional hackers), spies, non-professional hackers, activists, malware (virus/worm/etc.), etc. Common Terms Following are the common terms frequently used to define computer threat − Virus Threats A computer virus is a program designed to disrupt the normal functioning of the computer without the permission of the user. Spyware Threats Spyware is a computer program that monitors user’s online activities or installs programs without user’s consent for profit or theft of personal information. Hackers Hackers are programmers who put others on threats for their personal gain by breaking into computer systems with the purpose to steal, change or destroy information. Phishing Threats It is an illegal activity through which phishers attempt to steal sensitive financial or personal data by means of fraudulent email or instant messages. How to Secure Your Computer System from Threats? Following are the significant tips through which you can protect your system from different types of threat − Install, use, and keep updated Anti-Virus in your system. Install, use, and keep updated a Firewall Program. Always take backups of your important Files and Folders. Use Strong and Typical Passwords. Take precaution especially when Downloading and Installing Programs. Install, use, and keep updated a File Encryption Program. Take precaution especially when Reading Email with Attachments. Keep your Children aware of Internet threats and safe browsing. Print Page Previous Next Advertisements ”;

Basics of Computer Science – Quick Guide ”; Previous Next Fundamental Concept A computer is basically a programmable machine capable to perform arithmetic and logical operations automatically and sequentially. It is also known as a data processor, as it can store, process, and retrieve data as per the wish of the user. Data processing involves the following three activities − Input of data Manipulation/processing of data Giving output (i.e. management of output result) In computer system, data is arranged orderly and systematically. The term “computer” is derived from a Latin term “compute,” which means ‘to calculate.’ Initially, the computer system had been designed to calculate; it was intended to be a computing device. However, over a period of time, this device technically advanced; at present, it can perform a wide range of desirable works apart from data processing. Major Functions of Computer System Following are the core functions of a computer system − A computer accepts the command and/or data as input given by the user. A computer follows the instructions and stores the data given by the user. A computer processes the data as per the instructions given by the user. A computer gives the desirable results in the form of output. Salient Features of Computer System Following are the salient features of a Computer System − Automation − The operating system of a computer system is automatic, as no human intervention is required; simply you need to give the command and then it will do the work automatically. Speed − Depending upon the power of the computer, it can perform, it can take Millions of instructions per second. Storage − A computer system can store enormous quantity of data in different format. The storage capacity of a computer system is normally expressed in terms of Kilobytes (KB), Megabytes (MB), Gigabytes (GB), or Terabytes (TB). Accuracy − The accuracy of a computer system is very high. Versatility − A computer system is capable of performing a wide range of tasks. Diligence − A computer neither get tired nor lose concentration. Reliability − As a computer system always gives accurate result; therefore, its reliability is very high. Vast memory − A computer system can have a wide range of memory which can recall the desired data at any point of time. Evolution of Computer System The present Computer System has evolved after centuries of efforts from different intellectuals who contributed their works during different periods of time. Abacus is (most likely) considered as the earlier counting device. Let us now read about the innovators who contributed immensely in the development of a computer system. John Napier Napier was a Scottish mathematician who invented logarithms. Further, Napier also invented a computing device, which consisted of sticks with numbers imprinted on them. Napier named sticks ‘bones,’ as they were made up of bones. Blaise Pascal Pascal was a French mathematician who invented a machine based on gear wheels, which helped greatly in calculation. Charles Babbage Babbage was an English Polymath, Mathematician, Mechanical Engineer, Philosopher, and Inventor. In 1822, he developed a machine capable to calculate the successive difference of expression and prepared a table which helped him in his calculations. Lady Ada Lovelace Lovelace was an English mathematician, who researched on Babbage’s work. She has given the concept that ‘computers can be programmed’. Her work helped a great deal in the advancement of computer system. John Atanstoff With the assistance of Berry, John Atanstoff developed the Atanstoff Berry Computer (more popular as ABC) in 1937. It marked the beginning of the development of electronic digital computer. John Mauchly and Eckart In 1947, John Mauchly and Eckart developed the first large scale Electronic Digital Computer. It was called the Electronic Numerical Integrator and Calculator (ENIAC). Maurice V. Wilkes In 1949, Wilkes (at Cambridge University) designed Electronic Delay Storage Automatic Calculator (EDSAC). It was the first computer that started its operating system on the stored program concept. Role of Computer in Today’s World In today’s world, for almost every activity whether personal (for example, operating personal savings bank account) or business-related (for example, selling any product or services); in some or the other way, we rely on the computer system. Due to the growing dependency on computers, every small and big organizations and other business companies have started offering computer-based service. Furthermore, the advancement of communications, electronic service networks, and multimedia have opened a new door for corporates by providing an effective way of business processing, payment transfer, and service delivery. Advantages of Computers in Business Following are the major advantages of introducing computer system in business − Independency As computers help in making the business automated, the businesses are becoming more and more independent. No more, there is the need to put man-power for every work, as with the help of computer most of the works can be automated. Starting from ticket booking to a luxury car manufacturing, everything is automated. Cost Cutting A number of business are based online in recent times; therefore, there is no need to open business branch in every city, rather having one centralized inventory can make the business easier. There is no need to employ many man-power. Marketing With the use of computer system with Internet facility, it is very simple to make a business global in a given period of time. Website, email, social media websites, online advertisements, etc. are the important tools of online marketing. Huge Transaction Capacity A number of tasks are being done by computer including ticket booking to money transactions; this increases the transaction capacity. Huge Storage Capacity Normally,

Basics of Computer Science – Multimedia ”; Previous Next In this chapter, we will discuss how the Computer Multimedia works. If a system presents, some information through more than two media, it is known as multimedia. For example, TV presents audio and video; book presents text, image, and graphs, computer, etc. The information presented through multimedia has better quality and capability, as it can be understood easily. The advanced computer system is a great example of modern multimedia. Literal Meaning of Multimedia In this section, we will understand the literal meaning of multimedia. Multi − it means more than one Medium − it is singular and it means intermediary or mean Media − it is plural and it means conveying the information Likewise, Multimedia is the field of Computer Science that integrates different forms of information and represents in the form of audio, video, and animation along with the traditional media, i.e., text, graphics/drawings, images, etc. Multimedia Computer System Multimedia computer system has high capacity to integrate different media including text, image, graphics, audio, and video. The multimedia computer system stores, represents, processes, manipulates, and makes available to users. Significant Features of Multimedia Computer System Following are the major features multimedia computer system − Its Central Processing Unit (CPU) is very fast, as it needs to process large amount of data. It has huge storage capacity. It has huge memory power that helps in running heavy data programs. It has high capacity graphic card that helps in displaying graphics, animation, video, etc. The sound system makes it easy to listen to audio. With all these features (discussed above), a computer system is known as high end multimedia computer system. However, all the features listed above are not essentially required for every multimedia computer system, but rather the features of a multimedia computer system are configured as per the need of respective user. Multimedia Components Following are the major components of a multimedia computer system − Text It contains alphanumeric and some other special characters. Keyboard is usually used for input of text; however, there are some internal (inbuilt) features to include such text. Graphics It is technology to generate, represent, process, manipulate, and display pictures. It is one of the most important components of multimedia application. The development of graphics is supported by a different software. Animation Computer animation is a modern technology, which helps in creating, developing, sequencing, and displaying a set of images (technically known as ‘frames’). Animation gives visual effects or motion very similar to that of a video file (see image given below). Audio This technology records, synthesizes, and plays audio (sound). There are many learning courses and different instructions that can be delivered through this medium appropriately. Video This technology records, synthesizes, and displays images (known as frames) in such sequences (at a fixed speed) that makes the creation appear as moving; this is how we see a completely developed video. In order to watch a video without any interruption, video device must display 25 to 30 frames/second. Multimedia Application Let us now see the different fields where multimedia is applied. The fields are described in brief below − Presentation With the help of multimedia, presentation can be made effective. E-books Today, books are digitized and easily available on the Internet. Digital Library The need to be physically present at a library is no more necessary. Libraries can be accessed from the Internet also. Digitization has helped libraries to come to this level of development. E-learning Today, most of the institutions (public as well as private both) are using such technology to education people. Movie making Most of the special effects that we see in any movie, is only because of multimedia technology. Video games Video games are one of the most interesting creations of multimedia technology. Video games fascinate not only the children but adults too. Animated films Along with video games, animated film is another great source of entertainment for children. Multimedia conferencing People can arrange personal as well as business meetings online with the help of multimedia conferencing technology. E-shopping Multimedia technology has created a virtual arena for the e-commerce. Print Page Previous Next Advertisements ”;

Basics of Computer Science – Security ”; Previous Next Advancement of computer technology has radically changed the world; resultantly, most of the works whether it is matter of nation’s security system or buying a shoe online everything depends on computer. Such increased dependency also raises the issue of security, as most of the data is now stored in the computer system. Your computer systems store various sorts of data and hence if it is not secured, then you might be in for a big trouble. Why Do We Computer Security? Let us now see why do we need Computer security. It is required for the following major reasons − To prevent damage of the hardware. To prevent theft or damage of the installed software. To prevent theft or damage of stored data and information. To prevent the disruption of service. Likewise, security system keeps the computer system safe by protecting the installed software and the stored data (information). Protection of Data and Information Following are the important steps to protect data − Make backup of all your important files. Keep your system virus by using anti-virus software. Keep updating your computer system. Run disk defragmenter and disk cleanup on certain interval of time. Use a firewall. Use anti-spyware software. Further, if you use internet, then you need to take greater precaution. Consider the following points to understand the precautions that need to be taken − Do not click on any link that you don’t know (as it may be dangerous for your computer – virus attack). Do not open unauthorized an unlawful website (it may damage your computer system). Do not download unsolicited data from unknown website. What is Defragmentation? Frequent saving and deleting of file (data) from the hard disk creates problems in performance and also reduce the space; therefore, defragmentation again clean-up the drive and restore the system to run smoothly. Following are the simple steps of defragmentation − Disk Cleanup While browsing websites (on internet), many of the files get stored in the hard disk automatically (actually these stored files later help to reopen the website faster); besides some other cookies also get stored in the hard disk. All these stored files create problem along with eating space. So, disk cleanup process cleans all these files and releases the space occupied by these unwanted files. Following are the simple steps of disk cleanup − Print Page Previous Next Advertisements ”;

Basics of Computer Science – Extranet ”; Previous Next An extranet is a sort of personalized service, which is controlled and regulated by private network. This personalized and controlled technology provides access only to partners, vendors, and suppliers; sometimes, not essentially, but also to some specific customers. An extranet is a private network organization, which is actually the part of respective company’s intranet and its services are extended to users outside the company. Sometimes, it is also considered as a specialized technique to practice business with other companies and selling products to the customers. In order to do business with other business partners, extranet technology facilitates the intranet from one location to other and also provides security to data flow. An extranet service requires firewall server management in order to provide security and privacy. Features of Extranet Services Following are the significant features of extranet services − Extranet is an extended Internet service to the private business network. The services extend outside the corporate firewall. Sometimes, it can be referred to an Intranet, as it can be (partially) accessible to some outsiders (with permission). The technique of extranet links two (or more) business organizations who share common business goals. Application of Extranet Extranet can be applied for the following services − It facilitates collaborative business between two (or more) companies By using this technology, a joint training program (with other company) is conducted By using electronic data interchange, large volumes of data are shared swiftly It is used to share product catalogs especially with wholesalers Extranet service is also used in providing customer support It is used to share business news with partner companies Advantages of Extranet The advantages of Extranet services are as follows − It makes business (services) swift and faster. It helps greatly in improving the business communication. It helps in reducing the cost (especially in terms of stationery stuff). It helps in improving the efficiency and confidence of the employees. It reduces some big physical barriers (especially the geographical distance). Major Fields Using Extranet Following are some of the major fields that are using Extranet service on a large scale − Corporate houses Government offices Education centers Intranet is more localized, as only internal employees have the accessibility. In contrast, Extranet covers a wider area, as outsiders (such as partner, vendor, or even customer) have the authorized accessibility. Print Page Previous Next Advertisements ”;

Computer Science: Development ”; Previous Next In this chapter, we will discuss the development in Computer Science chronologically. The following table lists down the development − Year Development 1959 Transistors: IBM 7090; IBM 1401 1962 NPN transistor 1963 Mouse; CMOS patented 1964 CDC 6600; IBM Data Cell Drive 1966 Integrated circuits: HP 2116A 1966 Apollo Guidance Computer 1969 Honeywell 316 1971 8″ floppy disk; ILLIAC IV 1973 Micral first microprocessor PC 1980 Sinclair ZX80, Seagate hard disk drive 1981 IBM PC, Acorn BBC Micro 1983 Apple Lisa; 3.5″ floppy 1984 Apple Mac; Apple Lisa 2 1988 Dell 1989 NeXT 1991 Apple Switches to PowerPC 1992 HP 95LX; Palmtop PC 1995 IBM Deep Blue chess computer 1996 USB 1.0 1997 Compaq buys Tandem; CD-RW 1998 iMac 2000 USB 2 2001 Apple iPod 2005 Mac Mini 2006 Apple transition to Intel 2007 iPhone 1 2008 USB 3.0 2010 Apple iPad 2012 IBM zEnterprise System Print Page Previous Next Advertisements ”;

Algorithm Flowchart ”; Previous Next A flowchart is a blueprint that pictorially represents the algorithm and its steps. The steps of a flowchart do not have a specific size and shape rather it is designed in different shapes and sizes (see the image given below). As shown in the above image, the boxes in different shapes and interconnected with arrows, are logically making a flow chart. A flow-chart represents the general steps in a process. Benefits of Flowchart Let us now discuss the benefits of a flowchart. Simplify the Logic As it provides the pictorial representation of the steps; therefore, it simplifies the logic and subsequent steps. Makes Communication Better Because of having easily understandable pictorial logic and steps, it is a better and simple way of representation. Effective Analysis Once the flow-chart is prepared, it becomes very simple to analyze the problem in an effective way. Useful in Coding The flow-chart also helps in coding process efficiently, as it gives directions on what to do, when to do, and where to do. It makes the work easier. Proper Testing Further, flowchart also helps in finding the error (if any) in program Applicable Documentation Last but not the least, a flowchart also helps in preparing the proper document (once the codes are written). Flow-Chart Symbols The following table illustrates the symbols along with their names (used in a flow-chart) − Name Symbol Name Symbol Flow Line Magnetic Disk Terminal Communication Link Processing Offline Storage Decision Annotation Connector Flow line Document Off-Page Connector Sample of Flow Chart Print Page Previous Next Advertisements ”;

Computer Science: Innovators ”; Previous Next The following table illustrates the names of major innovators with their works and year − Person Achievement Period/Year Pāṇini Pāṇini, the ancient Indian Sanskrit linguist, grammarian, and honorable scholar had systematized and mentioned the technical use of metarules, transformations, and recursions, in his book ”Ashtadhyayi.” It is considred as the forerunner to the computer programming language. 5th Century BC (about) Al-Khwārizmī Al-Khwarizmi had the technique of performing arithmetic with Hindu-Arabic numerals developed. 830 AD (about) Al-Jazari Al-Jazari had invented the programmable machines, namely programmable humanoid robots, and an astronomical clock, which is considered as the first programmable analog computer. 1206 AD (about) Ramon Llull Ramon Llull had designed multiple symbolic representations machines. 1300 AD (about) Blaise Pascal Pascal had invented the mechanical calculator. 1642 AD (about) Gottfried Leibniz Leibniz had developed the first-order predicate calculus, which were very important for the theoretical foundations of computer science. 1670 AD (about) Charles Babbage Babbage, who was popular as mathematician, philosopher, inventor and mechanical engineer, designed the Analytical Engine and developed a prototype for a less powerful mechanical calculator. Likewise, he originated the concept of digital programmable computer. Babbage is popular as “father of the computer”. 1822 AD (about) George Boole Boole conceptualized the Boolean algebra, which became the basis for digital logic and computer science. 1847 AD (about) Gottlob Frege Frege developed the first-order predicate calculus, which later became a crucial precursor requirement in developing the computation theory. 1879 AD (about) Herman Hollerith Hollerith invented the punched card evaluating machine and hence, he is popularly considered as the father of modern machine data processing. 1889 AD (about) Vannevar Bush Bush developed the Memex concept, which later led to the development of Hypertext. 1930 AD (about) Alonzo Church Church had developed the lambda calculus and found the un-decidability problem within it. 1936 AD (about) Stephen Cole Kleene Founded the computation theory. 1936 AD (about) Claude Shannon Founded practical digital circuit design. 1937 AD Konrad Zuse Built the first digital freely programmable computer of Z series. 1938 AD Tommy Flowers Designed and built the Mark Colossus computers, the world”s first programmable, digital, electronic, and computing devices. 1943 AD Max Newman Newman founded the Computing Machine Laboratory at the University of Manchester. It was the place where world”s first stored-program computer, the Manchester Small-Scale Experimental Machine was invented. 1943 AD John Mauchly & J. Presper Ecker Designed and built the ENIAC, the first modern computer, and the UNIVAC I, the first commercially available computer. 1943 AD Yoshiro Nakamatsu Invented the first floppy disk at Tokyo Imperial University. 1950 AD David Caminer & John Pinkerton Developed the LEO computer i.e. the first business computer 1951 AD Sergei Alekseyevich Lebedev Independently designed the first electronic computer in the Soviet Union (i.e. Ukraine). 1951 AD Grace Hopper Hopper wrote the A-O compiler (a sort of automatic programming language), which heavily influenced the COBOL language. 1952 AD Cuthbert Hurd Worked for the International Business Machines Corporation and developed first general-purpose computer, the IBM 701. 1952 AD Alan Perlis et al Developed the ALGOL programming language, and the first recipient of the Turing Award. 1952 AD Noam Chomsky Chomsky developed Chomsky hierarchy. He made contributions to computer science with his work in linguistics. 1956 AD Douglas Engelbart and Bill English Best known for inventing the computer mouse. 1963 AD Tadashi Sasaki Sasaki was an engineer at Sharp company and he conceived a single-chip microprocessor CPU. He also developed LCD calculators at Sharp. 1963 AD Dennis Ritchie and Ken Thompson Pioneered the C programming language and the Unix computer operating system at Bell Labs. 1967 AD Ken Thompson Thompson developed the Unix operating system, the B programming language, Plan 9 operating system, the first computer chess game and the UTF-8 encoding at Bell Labs. Further, he developed ”Go” programming language at Google. 1967 AD Adriaan van Wijngaarden Wijngaarden developed the W-grammar first used in the definition of ALGOL 68 1968 AD Masatoshi Shima Designed the Intel 4004, the first commercial microprocessor. 1968 AD Leslie Lamport Formulated algorithms to solve different fundamental problems in distributed systems (e.g. the bakery algorithm). 1974 AD Vint Cerf and Bob Kahn Designed the Transmission Control Protocol and Internet Protocol (TCP and IP), the primary data communication protocols of the Internet and other computer networks. 1978 AD Tim Berners-Lee Invented worldwide web. 1989 AD Tim Berners-Lee and Robert Cailliau Sent first HTTP communication between client and server. 1989 AD Print Page Previous Next Advertisements ”;

Basics of Computer Science – Virus ”; Previous Next A virus is a computer code or program, which is capable of affecting your computer data badly by corrupting or destroying them. Computer virus has the tendency to make its duplicate copies at a swift pace, and also spread it across every folder and damage the data of your computer system. A computer virus is actually a malicious software program or “malware” that, when infecting your system, replicates itself by modifying other computer programs and inserting its own code. Infected computer programs may include data files, or even the “boot” sector of the hard drive. Types of Virus Following are the major types of computer virus − Worms This is a computer program that replicates itself at a swift pace. Unlike a computer virus, it is self-contained and hence does not need to be part of another program to propagate itself. Trojan Horse A Trojan Horse is also a sort of destructive program that remains disguised in a normal software program. It is not exactly a virus, as it cannot replicate itself. However, there is possibility that virus program may remain concealed in the Trojan Horse. Bombs It is similar to Trojan Horse, but Logic bombs have some specialty; these include a timing device and hence it will go off only at a particular date and time. How Does Virus Affect? Let us discuss in what ways a virus can affect your computer system. The ways are mentioned below − By downloading files from the Internet. During the removable of media or drives. Through pen drive. Through e-mail attachments. Through unpatched software & services. Through unprotected or poor administrator passwords. Impact of Virus Let us now see the impact of virus on your computer system − Disrupts the normal functionality of respective computer system. Disrupts system network use. Modifies configuration setting of the system. Destructs data. Disrupts computer network resources. Destructs of confidential data. Virus Detection The most fundamental method of detection of virus is to check the functionality of your computer system; a virus affected computer does not take command properly. However, if there is antivirus software in your computer system, then it can easily check programs and files on a system for virus signatures. Virus Preventive Measures Let us now see the different virus preventive measures. A computer system can be protected from virus through the following − Installation of an effective antivirus software. Patching up the operating system. Patching up the client software. Putting highly secured Passwords. Use of Firewalls. Most Effective Antivirus Following are the most popular and effective antivirus from which you can choose one for your personal computer − McAfee Antivirus Plus Symantec Norton Antivirus Avast Pro Antivirus Bitdefender Antivirus Plus Kaspersky Anti-Virus Avira Antivirus Webroot Secure Anywhere Antivirus Emsisoft Anti-Malware Quick Heal Antivirus ESET NOD32 Antivirus Print Page Previous Next Advertisements ”;