Definition of information technology pdf

Peripherals sit outside the case external hardware such as mouse, keyboard, and monitor. Input Devices This unit contains devices with the help of which we enter data into the computer. This unit creates a link between the user and the computer. The input devices translate the data into a form understandable by the computer.

Most common are keyboard and mouse. Together, they are also called the CPU. It performs arithmetic and logic operations. The CPU is comprised of three main parts: i. Arithmetic calculations like as addition, subtraction, multiplication and division. Logical operation like compare numbers, letters, or special characters ii. Control Unit CU : controls and co-ordinates computer components.

Read the code for the next instruction to be executed. Increment the program counter so it points to the next instruction. Read whatever data the instruction requires from cells in memory. Provide the necessary data to an ALU or register. If the instruction requires an ALU or specialized hardware to complete, instruct the hardware to perform the requested operation. Memory It facilitates the remembrance power to computer system.

It refers to the physical devices used to store programs sequences of instructions or data e. The term primary memory is used for the information in physical systems which are fast i. RAM , as a distinction from secondary memory, which are physical devices for program and data storage which are slow to access but offer higher memory capacity. Primary memory stored on secondary memory is called virtual memory. RAM Random Access Memory RAM RAM is a memory scheme within the computer ter ssystem responsible for storing dataa ono a temporary basis, so that it can be prompt mptly accessed by the processor as and when needed.

RAM is cons onsidered "random access" because you can acce ccess any memory cell directly if you know thee ro row and column that intersect at that cell. Volatile Memory RAM Volatile memory is computer ter memory m that requires power to maintain n the th stored information.

Static RAM retains its content tents as long as the power is connected and d is easy to interface to but uses six transistors perr bit. However, DRAM uses only one ne transistor and a capacitor per bit, allowing it to reach much higher densities and, with more mo bits on a memory chip, be much cheapeeaper per bit. Notice the positions of the cut cu out notches along the bottom of the DIMM indicated ated in red on the photograph above.

This is to make sure on only the correct RAM fits in the slot on the motherboard. You should be able to find this thi in the documentation that came with your computeuter. ROM stayss active ac regardless of whether power supply to it is turned on or off. ROM devices do not allow dat data stored on them to be modified. Non Volatile Memory ROM Non-volatile memory is compu mputer memory that can retain the stored informat mation even when not powered.

Cache Memory: Cache memory is random access acce memory RAM that a computer microp roprocessor can access more quickly than it can acces cess regular RAM.

As the microprocessor proc rocesses data, it looks first in the cache memory and if it finds the data there from a previous us reading r of data , it does not have to do the more ore time-consuming reading of data from largearger memory. It is of two types- L1 cache is on the he same s chip as the microprocessor. Hard drive HD : A hard disk is part of a unit, often called a "disk sk drive," d "hard drive," or "hard disk drive,"" that th store and provides relatively quick acces cess to large amounts of data on an electrom romagnetically charged surface or set of surfac rfaces.

Optical Disk An optical disc drive ODD is a disk drive that uses laser light as part of the process of reading or writing data to or from optical discs. Some drives can only read from discs, but recent drives are commonly both readers and recorders, also called burners or writers. Compact discs, DVDs, and Blu-ray discs are common types of optical media which can be read and recorded by such drives. Optical drive is the generic name; drives are usually described as "CD" "DVD", or "Blu-ray", followed by "drive", "writer", etc.

Blu-ray discs, which are the newest type of optical media, can store up to 50 GB of data. This storage capacity is a clear advantage over the floppy disk storage media a magnetic media , which only has a capacity of 1.

The format offers more than five times the storage capacity of traditional DVDs and can hold up to 25GB on a single-layer disc and 50GB on a dual- layer disc. Units of Memory: The smallest unit is bit, which mean either 0 or 1. Flash Disk A storage module made of flash memory chips. A Flash disk have no mechanical platters or access arms, but the term "disk" is used because the data are accessed as if they were on a hard drive. The disk storage structure is emulated. Output devices An output device is any piece of computer hardware equipment used to communicate the results of data processing carried out by an information processing system such as a computer which converts the electronically generated information into human readable form.

Those are devices which help to display the processed information. Monitor or screen ii. LCD Projection Panels iii. Printers all types iv. Plotters vi. Speaker s vii. On the basis of working principle i. Analog Computer An analog computer is a form of computer that uses continuous physical phenomena such as electrical, mechanical, or hydraulic quantities to model the problem being solved. Digital Computer A computer that performs calculations and logical operations with quantities represented as digits, usually in the binary number system.

A hybrid computer system setup offers a cost effective method of performing complex simulations. The instruments used in medical science lies in this category. On the basis of Size i. Super Computer The fastest type of computer, Supercomputers are very expensive and are employed for specialized applications that require immense amounts of mathematical calculations.

For example, weather forecasting requires a supercomputer. Other uses of supercomputers include animated graphics, fluid dynamic calculations, nuclear energy research, and petroleum exploration.

Mainframe Computer A very large and expensive computer capable of supporting hundreds, or even thousands, of users simultaneously. In the hierarchy that starts with a simple microprocessor in watches, for example at the bottom and moves to supercomputers at the top, mainframes are just below supercomputers. In some ways, mainframes are more powerful than supercomputers because they support more simultaneous programs.

But supercomputers can execute a single program faster than a mainframe. Mini Computer A mid-sized computer, in size and power, minicomputers lie between workstations and mainframes. In the past decade, the distinction between large minicomputers and small mainframes has blurred, however, as has the distinction between small minicomputers and workstations.

But in general, a minicomputer is a multiprocessing system capable of supporting from 4 to about users simultaneously. Generally, servers are comes in this category. Micro Computer: a. Desktop Computer: a personal or micro-mini computer sufficient to fit on a desk. Laptop Computer: a portable computer complete with an integrated screen and keyboard. It is generally smaller in size than a desktop computer and larger than a notebook computer.

Palmtops have no keyboard but the screen serves both as an input and output device. Workstations A terminal or desktop computer in a network. In this context, workstation is just a generic term for a user's machine client machine in contrast to a "server" or "mainframe. The instructions given to the computer in the form of a program is called Software. Software is the set of programs, which are used for different purposes.

All the programs used in computer to perform specific task is called Software. Software Types Software is often broken into two major categories: System Software that provides the basic non task-specific functions of the computer, and Application Software which is used by users to accomplish specific tasks. System software is responsible for controlling, integrating, and managing the individual hardware components of a computer system so that other software and the users of the system see it as a functional unit without having to be concerned with the low-level details such as transferring data from memory to disk, or rendering text onto a display.

It hosts the several applications that run on a computer and handles the operations of computer hardware. Example of Use: e. They are popularly associated with Desk Top operating systems which run on standalone systems where no user accounts are required.

Example: DOS. Refers to computer systems that support two or more simultaneous users. Another term for multi-user is time sharing. Example: All mainframes are multi-user systems. Distributed computations are carried out on more than one machine. When computers in a group work in cooperation, they make a distributed system. Commonly used operating system UNIX: Pronounced yoo-niks, a popular multi-user, multitasking operating system developed at Bell Labs in the early s.

UNIX was one of the first operating systems to be written in a high-level programming language, namely C. This meant that it could be installed on virtually any computer for which a C compiler existed.

A freely-distributable open source operating system that runs on a number of hardware platforms. The Linux kernel was developed mainly by Linus Torvalds and it is based on Unix. Because it's free, and because it runs on many platforms, including PCs and Macintoshes, Linux has become an extremely popular alternative to proprietary operating systems.

Windows: Microsoft Windows is a series of graphical interface operating systems developed, marketed, and sold by Microsoft. The most recent client version of Windows is Windows 10; the most recent server version is Windows Server R2; the most recent mobile version is Windows Phone 10 Windows 10 Mobile was announced on January 21, , as a mobile operating system for smartphones and tablets with screens smaller than 8 inches, with the first build released on February 12, It is the successor to Windows Phone 8.

Windows Phone 8. Some features may vary depending on hardware compatibility. It superseded their earlier SunOS in Oracle Solaris, as it is now known, has been owned by Oracle Corporation since Oracle's acquisition of Sun in January This release aims more at the security part and comes with an easy to use application to harden your Desktop.

Mobile OS: A mobile operating system, also called a mobile OS, is an operating system that is specifically designed to run on mobile devices such as mobile phones, smartphones, PDAs, tablet computers and other handheld devices. The mobile operating system is the software platform on top of which other programs, called application programs, can run on mobile devices. Android is unique because Google is actively developing the platform but giving it away for free to hardware manufacturers and phone carriers who want to use Android on their devices.

Symbian OS combines middleware with wireless communications through an integrated mailbox and the integration of Java and PIM functionality agenda and contacts. Booting The process of loading the system files of the operating system from the disk into the computer memory to complete the circuitry requirement of the computer system is called booting.

There are three Language processors: A. Compiler: It is translator which converts the HLL language into machine language in one go. Interpreter: It is a translator which converts the High Level Language into machine language line by line. It takes one statement of High Level Language and converts it into machine code which is immediately executed. However, it is slow in processing as compare to compiler.

Assembler: It translates the assembly language into machine code. Terminologies: Registers: A register is a very small amount of very fast memory that is built into the CPU central processing unit in order to speed up its operations by providing quick access to commonly used values.

All data must be represented in a register before it can be processed. For example, if two numbers are to be multiplied, both numbers must be in registers, and the result is also placed in a register. You can think of a bus as a highway on which data travels within a computer. When used in reference to personal computers, the term bus usually refers to internal bus. This is a bus that connects all the internal computer components to the CPU and main memory.

All buses consist of two parts -- an address bus and a data bus. The data bus transfers actual data whereas the address bus transfers information about where the data should go.

The control bus is used by the CPU to direct and monitor the actions of the other functional areas of the computer. It is used to transmit a variety of individual signals read, write, interrupt, acknowledge, etc necessary to control and coordinate the operations of the computer. The size of a bus, known as its width, is important because it determines how much data can be transmitted at one time.

For example, a bit bus can transmit 16 bits of data, whereas a bit bus can transmit 32 bits. Clock speed: Also called clock rate, the speed at which a microprocessor executes instructions. Every computer contains an internal clock that regulates the rate at which instructions are executed and synchronizes all the various computer components. The CPU requires a fixed number of clock ticks or clock cycles to execute each instruction.

The faster the clock, the more instructions the CPU can execute per second. Clock speeds are expressed in megahertz MHz or gigahertz GHz. A bit microprocessor can process data and memory addresses that are represented by 16 bits.

A bit microprocessor can process data and memory addresses that are represented by 32 bits. Intel processor, Intel 64 bit Microprocessor: It indicates the width of the registers; a special high-speed storage area within the CPU. Pentium dual core, core 2 duo.

A bit microprocessor can process data and memory addresses that are represented by bits. RISC system has reduced number of instructions. Performs only basic functions. All HLL support is done in software. All operations are register to register. A large and varied instruction set. Performs basic as well as complex functions. All HLL support is done in Hardware. Memory to memory addressing mode EPIC Explicitly Parallel Instruction Computing : It is a bit microprocessor instruction set, jointly defined and designed by Hewlett Packard and Intel, that provides up to general and floating point unit registers and uses speculative loading, predication, and explicit parallelism to accomplish its computing tasks.

By comparison, current bit CISC and RISC microprocessor architectures depend on bit registers, branch prediction, memory latency, and implicit parallelism, which are considered a less efficient approach in micro-architecture design. Typically on older PCs, a modem, mouse, or keyboard would be connected via serial ports.

Serial cables are cheaper to make than parallel cables and easier to shield from interference. Also called communication port. It provides much higher data transfer speed in comparison with serial port. Also called Line Printer Port. USB is also much smarter and more versatile since it allows the "daisy chaining" of up to USB peripherals connected to one port. This type of port was invented by IBM. FireWire Port : The IEEE interface, developed in late s and early s by Apple as FireWire, is a serial bus interface standard for high-speed communications and isochronous real-time data transfer.

The interface is comparable with USB and often those two technologies are considered together, though USB has more market share. Infrared Port: An IR port is a port which sends and receives infrared signals from other devices. It is a wireless type port with a limited range of ft. Bluetooth: Bluetooth uses short-range radio frequencies to transmit information from fixed and mobile devices. These devices must be within the range of 32 feet, or 10 meters for Bluetooth to effectively work.

A Bluetooth port enables connections for Bluetooth-enabled devices for synchronizing. Typically there are two types of ports: incoming and outgoing. The incoming port enables the device to receive connections from Bluetooth devices while the outgoing port makes connections to Bluetooth devices.

It is an 8-bit code capable of coding characters. Unicode: It is a universal coding standard which provides a unique number for every character, no matter what the platform, no matter what the program, no matter what the language.

Unicode version 3. Application software: Are software used to accomplish specific tasks other than just running the computer system. Application software may consist of a single program, such as an image viewer; a small collection of programs often called a software package that work closely together to accomplish a task, such as a spreadsheet or text processing system; a larger collection often called a software suite of related but independent programs and packages that have a common user interface or shared data format, such as Microsoft Office, which consists of closely integrated word processor, spreadsheet, database, etc.

Computers use these little bits, which are composed of ones and zeros, to do things and talk to other computers. All your files, for instance, are kept in the computer as binary files and translated into words and pictures by the software which is also ones and zeros.

The decimal number system in contrast has ten unique digits, zero through nine. In addition to the microprocessor, a personal computer has a keyboard for entering data, a monitor for displaying information, and a storage device for saving data. A workstation is like a personal computer, but it has a more powerful microprocessor and a higher- quality monitor.

For example, a virus might attach itself to a program such as a spreadsheet program. Each time the spreadsheet program runs, the virus runs, too, and it has the chance to reproduce by attaching to other programs or wreak havoc. Some e-mail viruses don't even require a double-lick - they launch when you view the infected message in the preview pane of your e-mail software.

The program claims to do one thing it may claim to be a game but instead does damage when you run it it may erase your hard disk. Economics is a domain of social science, concerning the distribution, consumption and enactment of goods and services. Economics emphasis on Democracy as a word derives from Greek word demos, refers to a?

In many cultures it is the tradition to assume and subscribe the family name of their mate or spouse, which Irony is a medium in delivering message intentionally by using artistic devices or literary technique that is contrary to surface Information Technology Definition Information technology is an appliance of computer framework and assemblage of techniques, skills and methods in electronic networking.

What is Fortnight? What is Geography? What is Economics? What is Democracy? What is Maiden Name? What is Irony? Biology Definitions Glyosidic linkage : Glyosidic linkage is a covalent bond formed between Polysaccharides : Polysaccharides are macromolecules with a few hundred to Starch : Starch is a polymer of glucose monomers that Glycogen : Glycogen is a polysaccharide that animals store for