USB, or Universal Serial Bus, is a newer and much faster version of the serial port. It lets the notebook connect to a wide variety of devices, such as digital cameras, speakers, external hard disks, scanners, printers, etc. S, or Serial port , is used to attach external mice, keyboards, or other devices. Most notebooks have a serial port. P, or Parallel port , is used by most printers and many network connections.
Most notebooks have a parallel port.
M port is used to attach an external Monitor. Most notebooks have a monitor port . Most notebooks have this port, because this frees up the serial port for some other use. A is an Audio port . This means the notebook can accept input from a microphone or can transmit sound out via headphones or external speakers.