Serial Port:
To connect the external devices, found in old computers.
Parallel Port:
To connect the printers, found in old computers.
USB Ports:
To connect external devices like cameras, scanners, mobile phones, external hard disks and printers to the computer. USB 3.0 is the third major version of the Universal Serial Bus (USB) standard to connect computers with other electronic gadgets. USB 3.0 can transfer data up to 5 Giga byte/second. USB 3.1 and USB 3.2 are also released.
VGA Connector:
To connect a monitor or any display device like LCD projector.
Audio Plugs:
To connect sound speakers, microphone and headphones.
PS/2 Port:
To connect mouse and keyboard to PC.
SCSI Port:
To connect the hard disk drives and network connectors.
High Definition Multimedia Interface (HDMI):
High-Definition Multimedia Interface is an audio/video interface which transfers the uncompressed video and audio data from a video controller, to a compatible computer monitor, LCD projector, digital television etc.
