The port has either holes or a slot that matches the plug or card being connected into the port. A PS/2 port found on the back of computers that allows a keyboard and mouse with a PS/2 connector to be connected to the computer.
The bus connects major components like processor, memory and I/O internally and also connects the different external devices and ports thus expanding the computer's capabilities.

1. COM/Serial ports: [Component Object Model ]
It is used for connecting communication devices like modems or mice. Serial ports provide the serial transmission of data of one bit at a time. There are two types namely com ports – 9 pin ports and 25- pin ports.

2. Parallel ports:

Used to connect external input/output devices like scanners or printers. They facilitate the parallel transmission of data, of 1 byte (8 bits) at a time. Parallel ports use 25 pin RS- 232C.

3. Universal Serial Bus (USB) connectors:

• USB provide high-speed data transfer for Plug-n-play devices like keyboard, mice, scanners, printers, digital cameras, thumb drives, etc.,
• The data transfer speed in USB 1.0 is 12 Mb per second, USB 2.0 is 480 Mb per second and USB 3.0 is 5 Gb per second.
• USB allows multiple devices as many as up to 127 to run simultaneously on a computer.

The AGP is an advanced port designed for Video cards and 3D accelerators designed by Intel. AGP is to provide enhanced graphic accelerator cards, thus enhancing the picture quality of the screen.

4. PS/2 connectors:
Stands for “Personal System/2” (PS/2) are used to connect input devices like PS/2 keyboards or mice.

5. IDE drive connector:[lntegrated Drive Electronics]
IDE devices like Harddisk drives, CD-ROM drives are connected via a 40-pin ribbon cable.

6. Floppy drive connector:
Used for connecting the floppy drive to the PC. It is a 34-pin ribbon cable.