Digitizer or Graphic Tablet

Digitizer or Graphic Tablet
Digitizer is used for drawing new images or tracing old images. Usually. it is used for making maps and engineering drawings. A digitizer is also known as graphic tablet. It consists of a flat, rectangular board (or pad ) and an input device stylus or puck. Each location on the rectangular board points to corresponding positions on the computer screen. The Stylus or puck is connected to the board/pad by a wire.

Stylus looks like a pen. It is used for drawing images on a specially designed graphics screen or digitizer. Puck looks like a mouse. Puck is also called cursor. Usually, it is generally used for tracing old images

Software And Its Types

Software
Software tells the computer what to do and how to do. A computer performs different operations according to the instruction of software. Software is developed in a computer programming language.

Types of Software
Software can be classified into following two main categories or types
      1- System Software
      2- Application Software

System Software
A program or set of programs that is especially designed to control different operations of computer system is called system software. It controls the working of different components of the computer. The system also enables the other application programs to excute properly

Operating systems, utility programs, and device drivers are the examples of system software. Operating system is the main and most popular type of system software.

Application Software
A program or set of programs that are especially designed to solve the specific problems of users, are called application software. It is also known as software package

There are Different kinds of application software such as comercial software, scientific software, financial packages, Games, multimedia software.

Categories of Application software
The Application software is divided into two main categories
     1- Custom-built software
     2- Packaged software

Custom-built software
The software that is developed for a particular customer or organization is called custom-built software. It is also known as customized software. For example, software developed to  maintain the records of students of a particular collage is an example of custom-built software

Packaged Software
The software that is developed for sale to the general public is called packaged software. Packaged software is  used to solve some common problem of many people or users

Some examples of packaged software are ;
    1- Word processor such as MS-Word
    2- Spreadsheet such as MS-Excel
    3- Database software such as MS-Access
    4- Graphic software such as Adobe Photoshop and CorelDraw
    5- Communication Softwware such as Internet Explorer

Information Technology Introduction

Information Technology

The technology used for processing, storing, and communicating information is called information Technology or IT. It is the combination of telecommunication technology and computer technology. It combines computing with high-speed communication links for carrying data from one place to another. all over the world. The website is type of information technology


Following are major components of information technology.

    1- Data or Information
    2- Medium or communication network
    3- Computer hardware and software

Before information technology, telephone system was the only source of communication. Today, in addition to telephone system, fax machines, mobile phones, and computer network are the main sources of communication. The users can share and exchange information all over the world through computer network (Internet) or mobile phone networks. Computer hardware and software are playing main role in information technology.

The world has become a globel village due to information technology. The global village means the people living in the world know each other as if they are living in a village. People can exchange information or messages in such a manner as if they are sitting in a drawing room, face to face.

Primary Hardware Components

The primary Hardware components of computer system are shown in the following figure

                                                    CPU
                                                              ALU
                          Input Device             Control Unit              Output Device
                                                          Memory Unit
                                                       Secondary Storage

Input Device
The data and instructions are given to the computer as input. The input device is used to give input to the computer. It accepts input ( data & program instructions ) in a form that a computer can use. The most commonly used input devices are keyboard and mouse

Processor
Processor is the most important component of the computer. It is also known as Central Processing unit
(CPU). It is considered as the brain of the computer. It processes input data according to the given instructions, and converts it into useful information. It is is further divided into two main components. These are Control Unit (CU) and Arithmetic Logic Unit (ALU).

Memory Unit
The memory unit is another important part of computer. It is used to store data and instructions that are currently in use. The main memory or RAM is an example of memory unit.

Output Device
The Processed data is also known as output. The output device is used to get input from the computer. It gives processed data or results in form that a user can understand. The commonly used output devices are monitors and printers.

Secondary Storage Device
Secondary storage device is used to store data and programs permanently for later use. The commonly used secondary storage devices are hard disk, USB drive, floppy disk, and CD-ROM.