Theory - 86 :- PORT in Computer

WHAT IS PORT ?

Port is a connecting socket, outside the system into which different types of cables are plugged. It is a specific place from which other devices can be physically connected. I/O ports are the interfaces through which computers communicate with external devices such as printers, modems, joysticks and terminals. There are many types of ports used in computer system. Some of them are given as follows.

• Parallel Port
  

Various peripherals can be connected through parallel port, which is a parallel communication physical interface. A parallel port transmits 8 bits of a byte of data in parallel. It is used for transmitting fast data over short distances. It is used to connect a printer to a computer.

Since a parallel port transmits an entire byte at a time, it operates I/O devices at a relatively high speed. A Parallel port is primarily used to connect printers to a computer and hence it is often called a printer port.

 

• Serial Port 

Serial port transmits one bit of a byte, one at a time as a single stream of bits.

It is meant for transmitting slow data over long distances. Communication over a phone is an example of serial communication. It is a serial communication physical interface which transmits one bit at a time. Dial-up modems and serial mice use serial ports.

 

• Universal Serial Bus (USB) 

A USB Port can connect up to 127 peripheral devices such as a digital camera, digital speakers, scanners, speakers etc.

It permits Plug and Play – configuring of expansion cards and peripheral devices as and when they are installed.

• Small Computer System Interface (SCSI) Port 
  

SCSI-Small Computer System Interface Port allows data to be transmitted in a daisy chain to up to 7 devices at a speed higher (32 bits at a time) than those possible with serial and parallel ports.

It is a fast data transmitting device and is used to connect HDD, CD ROM drives and scanners with the computer system