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Here you can explore the complete information of Information Technology.
The acquisition, processing, storage and dissemination of vocal, pictorial, textual and numeric information by a micro-electron based combination of computing and telecommunication. OR Information Technology is a merging of computing and telecommunication.
Collection of information is called data. OR General term for numbers , symbols, and quantities that serve as input for computer processing are called data.
Data is a collective noun and may be either singular or plural. Different pieces of data combine to form complete information about anything.
Data processing is the process of changing data to acquire the desired result. OR Data Processing is a process of collecting the data together and converting the data into information. The method used for collecting the data may be manual, mechanical or electronic.
There are many types of data processing systems. These systems vary in size, complexity, speed, cost and application. A computer based data processing cycle has four basic components i.e. machine, program, data and people. Machines and programs are hardware and software. The major steps involve in data processing consists of three basic steps:
The information that is delivered to data-processing device from the external world, the process of delivering this data or equipment that performs this process is referred to as input. Input may contain any type of data - commercial, engineering, scientific, statistical and so on.
To assemble, compile, generate, interpret, compute and otherwise act in information in a computer is referred to as Process.
The data processed by a data-processing operation or the information that is objective or goal in data processing is referred to as Output.
The smallest piece of data that can be recognized and used by a computer, is the bit, a binary digit. A bit is a single binary value, either a 1 or 0. A group of eight bits is called a byte. The byte is the basic unit for measure of the size of the memory, with today’s computer memory sizes. It is more common to hear the term kilobyte (KB) or megabyte (MB).
Hardware is the term used to describe the electrical and mechanical parts of the computer as well as the peripheral devices. In other words the physical, tangible and permanent components of a computer are referred to as Hardware. Hardware is made up of various metal, silicon and plastic components. It can basically be divided into four segments: a central processing unit, input devices, output devices and memory. We select specific components according to the function we want the machine to perform.
MAJOR PARTS OF HARDWARE Some of the major parts of hardware are listed below:
It is important to note that computer cannot do anything on its own. It must be instructed to do our desired job. It is the program that controls the activity of processing by the computer and the computer performs precisely what the program wants it to do. The term software refers to the set of computer programs, procedures. To be precise software means a collection of programs whose objective is to enhance the capabilities of hardware machine. Computer software is normally classified into two broad categories. 1. Application software 2. System software Application software is also known as an application package is a set of one or more programs designed to carry out operations for a specified application e.g., a pay roll package produces pay slips as the major output and an application package for processing examination results produces mark sheet. Similarly a program written by a scientist to solve his particular research problem is also an application software. System software also known as a system package is a set of one or more programs designed to control the operations of computer system. These programs do not solve specific problems. They are general program written to as human in the use of computer system by performing task such as controlling all the operations required to move data into and out of the computer and all these steps in executing and application program. In general system packages support the running of other software, communicate with peripheral devices. System software makes the operation of the computer system more effective and efficient.
Computers are used in many field in the world, and some of the names are listed below:
The computer has following internal parts:
A data processing system's activities include input, processing and output. These activities make up the electronic data processing cycle. CPU supports the actual processing of data. Central Processing Unit is the brain of computer. We use CPU to control all input and output connections inside and outside of the computer and take a look on the programs that are currently present in a computer. In all PCs, CPU is the chip that runs programs. It carries out a variety of computations, numeric comparisons and data transfers in response to programs stored in memory. The CPU response the computer's basic operation by sending and receiving control signals, memory addresses and data from one part of the computer to another along a group of interconnecting electronic pathways called a BUS. Located along the bus are input and output (I/O) ports that connect the various memory and support chip to the bus. Data passes through these I/O ports while it travels to and from the CPU and the other parts of computer. Any computer must contain three of the following fundamental units:
The control unit essentially governs all computer activities and monitors the execution of programs. It coordinates and controls the computer system much as the brain directs the body. Once it has executed an instruction, the control unit must determine where to store the results for series of operations for each instruction.
The Arithmetic & Logic Unit (ALU) performs the addition, subtraction, addition with carry, subtraction with borrow, incrementing, decrementing, ANDing, ORing, shifting, moving, comparing, storing, temporarily holding the results in a storage unit known as the ACCUMULATOR. The ALU is responsible for performing all arithmetic and logic operations and transferring data between storage locations. The ALU also handles logic operations. Logic operations involve comparisons. Logic operation can use numeric, alphabetic or alphanumeric quantities. The sign (negative or positive) and the value of the difference tell the processor that the first number is equal to, less than, or greater than the second number. Alphabetic data may also be compared according to an assigned order sequence.
The storage capacity of the CPU is called the Primary Storage Unit. Over the years the storage unit has been called Main Storage, Primary Storage, Core or Memory. Primary storage provides the capability to store input data, statements from programs currently undergoing processing, data resulting from processing and data in preparation for output. Data input to the computer stays in primary storage until it is used in processing. During processing, primary storage is used to store the intermediate and final results of all arithmetic and logical operations. The computer's primary storage unit is easily accessible to the CPU. The main memory is also called primary storage memory is used for four purposes. Three of these relate to the data being processed: Data are fed into an input storage area where they are held until ready to be processed. A working storage space that's like a sheet of scratch paper is used to hold the area being processed and the intermediate results of such processing. Output storage is holds the finished results of the processing operations until they can be released. In addition to these data-related purposes, the primary storage section also contains a program storage area that holds the processing instructions.
Every computer has a storage area to store any kind of information for temporary use. We call this area as Internal Storage or Memory of a computer. Internal memory is used to store software and data currently being processed. The software comprises the operating system and the application program. The internal memory provides the means by which the control unit gains fast access to the next to be processed and the data, which is currently being operated on. OR A device or medium that can accept data, hold them, and deliver them on demand at a later time is referred to as Memory. These are two of the following types of memory in a computer:
It is a kind of memory used for temporary purpose, when we turn off the power of computer the contents of memory is lost. Upon reapplying power to the computer, the data must rewritten into the memory area. As a general rule, higher speeds of operation can be used for the read/write cycles. Volatile memory is also called Random Access Memory (RAM) or Read Write Memory (RWM).
RANDOM ACCESS MEMORY (RAM) The kind of memory used to read/write any program is called Random Access Memory (RAM). It is a memory, a computer always busies to read and write any kind of information to get the required result. In this memory we can store data, values programs and results for temporary use. RAM in any computer system plays very important role because it is an area where the computer can be able to handle and process our provided values by the help of a well-defined sequence of instructions called a Program. New types of RAM are available nowadays. Some names of memory based on the Random Access Metallic Oxide Semi-conductor (MOS) are listed below:
It is a kind of memory, which is used for permanent purposes; it is not lost when the power is turned off because they are permanently built in the system. Some kinds of non-volatile memory are listed below:
READ ONLY MEMORY Some of the systems programs that the computer needs to manage its operations are permanently built into it and they are called Read Only Memory (ROM). this memory contains programs that are used to check all connections inside the computer and controls its work. The program present in the ROM can never be changed, deleted or lost if we switch off the power of computer. The ROM chip contains a program named BIOS. BIOS stands for Basic Input Output System, which is a program, used to control the working of computer.
Language is a system for representation
and communication of information or data. Like human beings, a language or
signal is required to communicate between two persons. Similarly, we
cannot obtain any result by computer without langtage. Computer does not
understand directly what we are communicating with computer as English or
Arabic, it understands only machine language (binary codes 0-1). Computer
translates English language into machine codes through interpreter then
process instructions and give us the results. The computer languages can be divided
into two main levels.
Symbolic
languages are further divide into two main levels
Although computers can be
programmed to understand many different computer language. There is only
one language understood by the computer without using a translation
program. This language is called the machine language or the machine
codes. Machine codes are the fundamental language of the computer and is
normally written as strings of binary 0-1. ADVANTAGES AND LIMITATIONS OF MACHINE
LANGUAGE Programs written in machine language can
be executed very fast by the computer. This is mainly because machine
instructions are directly understood by the CPU and no translation of
program is required. However, writing a program in
machine language has several disadvantage. MACHINE DEPENDENT Because the internal design of
every type of computer is different from every other type of computer and
needs different electrical signals to operate. The machine language also
is different from computer to computer. DIFFICULT TO
PROGRAM Although easily used by the computer,
machine language is difficult to program. It is necessary for the
programmer either to memorize the dozens of code number for the commands
in the machine’s instruction set or to constantly refer to a reference
card. DIFFICULT TO
MODIFY It is difficult to correct or modify
machine language programs. Checking machine instructions to locate errors
is difficult as writing them initially. In short, writing a program in machine
language is so difficult and time consuming. In symbolic languages, alphabets are used
(a-z). symbolic languages are further divide into two main levels.
A language is one step higher than
low-level languages in human readability is called high-level language.
High – level languages are easy to understand. They are also called
English oriented languages in which instruction are given using words.
Such as add, subtract, input, print, etc. high level language are very
easy for programming, programmer prefer them for software designing
that’s why these languages are also called user’s friendly
languages. Every high level language must be converted into
machine language before execution, therefore every high level language has
its own separate translating program called compiler or interpreter.
That’s why some time these languages are called compiler langauges.
COBOL, BASIC, PASCAL, RPG, FORTRAN are some high level languages. INTERPRETER An interpreter is a set of programs which
translates the high-level language into machine acceptable form. The
interpreters are slow in speed as compared to compilers. The interpreter
takes a single line of the source code, translates that line into object
code and carries it out immediately. The process is repeated line by line
until the whole program has been translated and run. If the program loops
back to earlier statements, they will be translated afresh each time
round. This means that both the source program and the interpreter must
remain in the main memory together which may limit the space available for
data. Perhaps the biggest drawback of an interpreter is the time it takes
to translate and run a program including all the repetition which can be
involved. A
language which is one step higher than machine language in human
readability is called Assembly Language or a low-level language. In an
assembly language binary numbers are replaced by human readable symbols
called mnemonics. Thus a low-level language is better in understanding
than a machine language for humans and almost has the same efficiency as
machine language for computer operation. An assembly language is a
combination of mnemonic, operation codes and symbolic codes for addresses.
Each computer uses and has a mnemonic code for each instruction, which may
vary from computer to computer. Some of the commonly used codes are given
in the following table. An
assembly language is very efficient but it is difficult to work with and
it requires good skills for programming. A program written in an assembly
language is translated into a machine language before execution. A
computer program which translates any assembly language into its
equivalent machine code is known as an assembler.
INPUT The information entered into the computer for processing purposes is termed as input.
INPUT DEVICES Any peripheral that assist us in getting data into the computer, such as a keyboard, mouse, trackball, voice recognition system, graphical tablet or modem is termed as Input Device. There are a number of input devices available to input data into the computer system. Without these devices computer never perform any kind of work. These are the essential part used with computers and are listed below:
A device used to feed information into the computer in the shape of alphabets, numbers, puntuation marks, graphic symbols and foreign currency marks in know as Keyboard. They are used for inputting data at a comparatively very slow rate of human typing. Their major function is to enable the computer to communicate with the computer operator.
Mouse is another input device usually referred to as Pointing device. With the help of mouse we can move around the screen with no time. Nowadays mouse is always installed on AT-type computers. All type of mouse manufactured from different vendors available with two or more than two keys or buttons and a small ball, which is the guiding part where you wants to move the pointer on the screen to select any kind of option. These selections are available under WINDOWS. Mouse has a cable and a plug, which is installed into the computer from rear side with the mouse port.
Any type of joystick is always used to play games on the computer. This is an input device always used to control all possible movement around the screen during playing games. Any joystick has switches for firing and a vertical stick placed at the 90°, which is used to move and control any kind of object.
OUTPUT The process of displaying or printing the results of processing operations is called Output.
OUTPUT DEVICES A number of different Output Devices are available for use on computer items and various combinations of them will be found in common use. The main form of computer output for human use is the printed report with the help of Printers. The general use of output devices are
A visible representation of information, in words, numbers or drawings, as on the cathode-ray tube or screen of a radar set, navigation system or computer console is referred to as Monitor. OR It is a device on which the information is projected.
A computer output mechanism that prints characters one at a time or one line at a time. OR A printer is one of the most common computer output devices used in business applications. It takes data that has been processed by the computer and print it on continuous forms.
An operating system is a program or an organized collections of programs and data prepared by software Designers to perform such operations as managing computer resources, scheduling and supervising work, operating and controlling mechanical devices. In other words an operating system tells the computer what to do and how to do it. PC operating systems are program products that enhance the performance of specific tasks. The operating loads and readies program for operation. Operating systems normally include a number of utility programs in addition to the control software. Operating systems is some time referred to as Systems software. Different name of operating systems are listed below:
Here are some description of operating systems:
It is a collection of programs reside on the disk. DOS is a single user operating system used with microcomputers, which provides the communication link between user and hardware. DOS plays a vital role in operation of a computer system. It facilitates the user to copy, print, delete, rename etc a file. The DOS contains three main files COMMAND>COM, IO.SYS, MSDOS.SYS and two types of commands.
INTERNAL COMMANDS Internal commands are those which are transferred into the memory at the time of booting the computer. These commands are the part of a program called COMMAND.COM. These commands are always available to the user although they cannot be displayed, delete, rename. Examples are CLS, TIME, DATE, COPY, VER.
EXTERNAL COMMANDS External commands are the conventional programs which are reside on the disk they do not transferred into the memory at the time of booting the computer. These commands can be displayed on the screen by taking the directory of a disk. External commands can be deleted, copy and even rename. Examples are diskcopy, format, xcopy, chkdsk, diskcomp, backup.
UNIX is a top-level operating system support multitasking, multi-user, time-sharing and network upto a number of terminals.
Features
XENIX is an improved and enhanced version of the AT&T UNIX System III, adopted or use by IBM PCs and its clones. Originally conceived at Bell Laboratories in 1969 by Dennis Ritchie, UNIX has grown to be a very popular operating system in the computer environment.
A series of operating system developed by Novell Inc. that runs in the servers and control system resources and information processing on an entire network or inter-network is called Netware Operating System.
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