output
No. VGA port is not either serial or parallel port. It is a different interface. If you need a serial output, you need a VGA to serial converter.
A USB port is both an input and an output.
output
input
Input/Output Controller Card
output cause the parallel port is outside the computer
Input port
wafi gila
The Universal Serial Bus (USB) port is an input/output port that allows the transfer of data from the computer's hard drive to the portable hard drive (e.g. flash drive). The port serves as the communication mechanism between the two hard drives.
USB ( Universal Serial Bus) serves both purposes...both output and input....when we copy something into a pen drive it serves as an output and when we view something from a pen drive it serves as an Input.
You would use a Loopback Plug, this allow an output signal to be returned as input.