Ports: how peripherals plug in

By the end of this lesson

By the end you can say what a port is, and compare USB, HDMI and VGA by what they carry and how they carry it.

Ports, plugs and peripherals

A port is a socket on the computer that lets an external device — a peripheral such as a keyboard, printer or monitor — connect and communicate with it.

Different ports carry different signals:

Port	Carries	Signal type
USB (Universal Serial Bus)	Data, and power to run or charge the device	Digital
HDMI (High Definition Multimedia Interface)	Video and audio	Digital
VGA (Video Graphics Array)	Video only	Analogue

Definition

Port

A physical socket on a computer through which data and control signals travel between the computer and a peripheral device.

USB carries any data plus power; HDMI carries digital video and audio; VGA carries analogue video only.

The three the syllabus names

USB. One connector style for many device types — mouse, printer, phone, memory stick. It sends data both ways, can supply power to the device, and supports hot-swapping: plugging in while the computer is on. Different versions (USB 2.0, USB 3.x) differ mainly in speed.
HDMI. One cable carrying digital video and digital audio to a monitor or TV. Because it is digital, the picture arrives exactly as it left the graphics card.
VGA. The older blue 15-pin connector. It carries an analogue video signal only — no sound — so a monitor needs a separate speaker cable.

Worked example: Choosing a connection

Match each job to the best port from USB, HDMI and VGA.

Have a go first?

Quick check

Multiple choiceQuestion 1 · Recall

Multiple choiceQuestion 2 · Apply

Fill in the blanksQuestion 3 · Apply

Answer the 3 questions above to continue.