IT Exam Outline PDF

IT EXAM OUTLINE WHAT IS A COMPUTER? A computer is an electronic device that can accept data and instructions, process them or store the for later retrieval, and sometimes generate output. ADVANTAGES OF USING A COMPUTER ​ Data can easily be accessed ​ Large amount of data can be stored i...

IT EXAM OUTLINE WHAT IS A COMPUTER? A computer is an electronic device that can accept data and instructions, process them or store the for later retrieval, and sometimes generate output. ADVANTAGES OF USING A COMPUTER ​ Data can easily be accessed ​ Large amount of data can be stored in a small amount of space. ​ Computers can work continuously and perform counter parts. ​ Keeps us updated on what is new. DISADVANTAGES OF USING A COMPUTER ​ Redundancy of jobs ​ The misuse of information. ​ Downtime (when a computer breaks down or data is corrupted) ​ The glare from the screen can cause eyestrain and inadequate support for the wrist when typing. Generations of computers - First Generation (It's period time is from (1940 - 1956) The first generation laptop was ENIAC (Electronic Numerical Integrator and Calculator). It had been the primary all-purpose electronic computer that is intended by William Mauchly and John Eckert in 1942 The machine was completed in 1945 and was designed to calculate artillery firing tables to be utilized by us Army’s trajectory research lab to assist North American country troops throughout war II. -Second Generation ( It's period time is from (1956 - 1963) The second generation computers were used during 1957-1963 and were known as transistor computers. The second generation of computers consists of two types of devices, transistors, and magnetic core. The transistors helped to develop a better computer than the first generation computers consisting of vacuum tubes. Some second generation of computers are IBM 1920, IBM 7094. The second generation of computers required less amount of energy (i.e. electricity) compared to the first generation of computers and produced less heat than the first-generation computer. Third generation (It's period time is from(1964 - 1971) The third generation computer was started in 1965 and ended around 1971 using integrated circuits instead of transistors. The integrated circuit (IC) is a semiconductor material, that contains thousands of smaller transistors in it. It was developed by Robert Noyce of Fairchild Semiconductor and Jack Kilby (American electrical engineer) of Texas Instruments in 1958. Third generation computers are much faster, efficient, reliable, less maintenance, and smaller in size. Fourth generation (It's period time is from (1971 – Present) The fourth-generation computers have microprocessor-based systems. It contained VLSI (Very Large Scale Integrated) Circuit or what is known as microprocessors and is utilized in this generation. A microprocessor chip is made from hundreds of Integrated Circuits construct on a single silicon chip. The fourth-generation computer used a microprocessor designed, developed, and invented by Intel Corporation in 1971. Fifth generation (It's period time is from (Present and Beyond) Fifth-generation computers, also known as modern computers, are still in the development stage and are based on artificial intelligence. The primary goal of the fifth generation is to create machines that can learn and organize themselves Has to do with the usage of AI, which helps to make computers more powerful. This is one of the primary elements of 5th generation computers. Types of computers 'SuperComputer' ​ Supercomputers is the general term given to the fastest computers in the world. ​ These computers are very large and may take several rooms due to their tremendous processing power. ​ They are used in fields that require vast amounts of complex mathematical calculations like weather simulations and nuclear research. ​ Super computer are used by: IBM and Microsoft MAINFRAME ​ Mainframes are extremely fast large computer systems. ​ They have a large number of terminals and peripheral devices because they are normally used by hundreds or thousands of persons. ​ Mainframes are used by: Banks, utility companies, airlines for making flight arrangements. MINICOMPUTER ​ Minicomputer is a multiprocessing computer system that is smaller and slower than a mainframe. ​ Mini computers are still a lot larger than the PC's people have at home. ​ Mini computers support fewer users than mainframes (200 users is the limit ) MICROCOMPUTER ​ Is a term used for computers that contain a microprocessor. ​ You guys know it as a PC (Personal Computer)  ​ The Desktops is usually supplied with separate units such as the tower, a monitor, keyboard, mouse and external speakers. ​ Laptops or notebooks are smaller portable computers. These come assembled in a smaller unit. Input Devices KEYBOARD ​ The keyboard is the most common input device available. ​ The Keyboard is best suited for data entry or typing text documents, even though they can be used for several other things. MOUSE ​ Is a hand-held device that is moved on the surface of the desk or on a mouse pad. ​ As the mouse moves, the cursor on the screen moves as well. ​ A mouse is commonly used for selecting a menu command or ' pressing' a button on the screen. THE JOYSTICK ​ Is a device with a stick perpendicular to its base, as well as buttons on the stick or the base. ​ It is primarily used in playing computer games or virtual reality. ​ An advantage is that it gives the user the feeling of a more realistic action. ​ Disadvantage is that it is limited to certain applications. THE OPTICAL MARK READER (OMR) ​ Is a device that senses the presence of pencil and pen marks that are made ​ on special forms. ​ Normally is used for exams that have or contain multiple choice  ​ Advantage is that it reduces the cost of inputting large volumes of data ​ Disadvantage Forms that are ceased jam the machine, causing downtime. THE OPTICAL CHARACTER READER (OCR) ​ Is a device that senses the presence of text by recognizing the character. ​ An OCR is used for reading postal codes, capturing data from airline ​ tickets. ​ Advantage: Quick method of inputting data ​ Disadvantage: it may misread characters that are not formed properly. THE SCANNER ​ Is a device used to scan images and text into a computer. ​ When a document is scanned it is imported as an image into a special ​ software. ​ Advantage: quick accurate method of entering images into a computer ​ Disadvantage: Some files require a large amount of space. OUTPUT DEVICES MONITOR ​ Is the part of a computer what we refer to as the screen. ​ Liquid Crystal Display (LCD) is seen in modern models. ​ These monitors are thinner and lighter. ​ Cathole Ray Tube (CRT) are bulky monitors that look like old fashioned TV's. PRINTERS ​ Is a device used to output text and images from a computer onto a piece of paper. ​ Printers can be Impact printer and non impact ​ Impact Printers: transfer data onto paper by hitting the paper with some part of the printer. Similar to a type writer. ​ Non Impact Printers: print using methods that do not involve striking the paper or ink ribbon. SPEAKERS ​ The speaker is an output device that is used to produce sounds. ​ It operates using the same principle as the stereo systems. ​ It creates electrical current that causes a diaphragm to vibrate thus creating or producing sound. Primary storage devices SECONDARY Storage Device Types of network(LAN,WAN,MAN) Topologies Microsoft word Mail Merge