Introduction to Data

 

Data is defined as the set or collection of facts and figures or any thing which can be fed to Computer is called data.

 

Facts

Data, which can’t be entered with the help of keyboard, can be called facts e.g. movies, songs, diagrams, maps, pictures etc.

 

Figures

Data, which can be entered with the help of keyboard, can be called figures. Figure data can be divided into three types:

1)            Alphabetic Data

2)            Numeric Data

3)            Alphanumeric Data

 

1)       Alphabetic Data

Alphabetic Data consists of alphabets (A-Z).

e.g. Haroon is very good boy.

 

2)       Numeric Data

Numeric Data consists of numbers (0-9) and special characters (symbols). e.g. 5+5=10

 

3)       Alphanumeric Data

Alphanumeric Data consists of both alphabetic and numeric data. e.g. Khalid Ph. No=621446

 

Introduction to Data Processing

 

To arrange data into a useful form is called data processing. We do it through Computer.

 

Information

To      process data into a usable form is called information. Thus the conversion of raw facts into a useable form is known as information.

 

Data Processing Cycle

Data processing cycle has three basic steps. These are:

 

1)            Input Cycle

2)            Processing Cycle

3)            Output Cycle

 

Input ŕ Processing ŕ Output

 

Input Cycle

Every source of data entered to Computer by user is called input cycle.

 

Input Devices

Devices used to enter data to Computer are called input devices.

 

Processing Cycle

After entering the data to Computer, Computer processes it to give us result/output. This step is called processing cycle.

 

Processing Unit

Parts of Computer where processing takes place are called processing unit.

 

Output Cycle

Once data is entered and processed, the results are to be brought out for the user. This is called output cycle.

 

Output devices

Devices used to give us results/information are called output devices.

 

Types of Data Processing

 

Data processing consists of four types:

1)            Manual Data Processing

2)            Mechanical Data Processing

3)            Electromechanical Data Processing

4)            Electronic Data Processing

 

1)       Manual Data Processing

When all the operations are done manually (by human beings) on data are called manual data processing.

 

2)       Mechanical Data Processing

When non-electronic machines like typewriters are used for data processing is called mechanical data processing.

 

3)       Electromechanical Data Processing

When simple electronic machines or non-programmable machines do data processing is called electromechanical data processing.

 

4)       Electronic Data Processing

It is the manipulation of raw facts using full automatic electronic machines like Computers. The main purpose of electronic data processing is to do a complex job of processing in short time. Electronic data processors process the instructions defined by the programmer.

 

Data Representation

 

Bit

Bit is the abbreviation of “Binary Digits” which is either “0” or “1” (0=OFF and 1=ON). Bit is the smallest unit in the field of data processing. In Digital Computers all the processing is done in the language of bits, which is the mother language of the Computer.

 

Byte

Combination of eight bits forms a byte. It is the basic unit of data because Computer storage is based on bytes. One byte is equal to one character.

 

8 Bits = 1B (Byte)

1024 B = 1 KB (Kilo-Byte)

1024 KB = 1 MB (Mega-Byte)

1024 MB = 1 GB (Giga-Byte)

 

File

Considering our daily school/college life, we say it is my Physics copy, English copy etc. Similarly in Computers copy is actually called file, in which we save, type, record our data, notes, applications, letters etc. Each file has its own name. These files are named according to our requirements.

 

Executable Files

Files used to start any program are called executable files.

 

Command

Set of instructions given to computer to perform special function is called command.

 

Program

A program is set of instructions written in a certain language. The programs written by a Computer user are called user programs.

 

Software

The programs used to run Hardware (or a Computer) are called Software.