Barcode And Barcode Reader

Barcode
Barcode is a unique identification code. It consists of light and dark vertical lines with spaces between them of different widths. Barcode is printed on most of the manufactured products. It represents the information about the product. Actually, the name of product, its price and other descriptions are coded as Barcode.
There are several bar-coding schemes or systems in use the most popular and commonly used barcode is UPC ( Universal Product Code )


Barcode ReaderBarcode reader is special scanning device. it is used fir reading ( or decoding ) barcode printed on the product or book. It uses laser beam to scan or read the barcode. It reads the barcode and translates it into digital signals. These Signals are input to the computer for further processing. The most common type of bar code reader is the flatbed scanner. it is commonly used in super markets and departmental stores

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.

Computer Basic Introduction

Computer
A computer is an electronic machine.it can be programmed to accept data process data into useful information, and store it for later use. A computer System consists of hardware and software

Software
Computer processes data according to the set of instructions given to it. The set of instructions given to the computer to perform a specific task is known as software. Software is also called computer program

Hardware
The physical components of a computer are called hardware. You can touch, see and feel hardware. The input/output devices ( such as keyboard, mouse, printer, monitor ), CPU, memory unit. are examples of hardware