In electronics, a circuit is a closed path that allows electricity to flow from one point to another. It may include various electrical components, such as transistors, resistors, and capacitors, but the flow is unimpeded by a gap or break in the circuit.

A flashlight is an example of a basic circuit. When the switch is off, the circuit is not closed, meaning electrical current will not flow from the batteries to the flashlight's bulb. When you move the switch to the on position, a piece of metal in the flashlight physically closes the gap in the circuit. Electricity from the batteries then flows to the bulb making it light up.

In computing, the term "circuit" is used more liberally and may be used to reference a circuit board or an integrated circuit. The internal workings of computers and other electronic devices are comprised of these components, which may each contain hundreds or thousands of individual circuits.

The large number of circuits inside computers allow them to route data to different locations and perform complex calculations. For example, a chip may route graphics operations to the GPU and other operations to the CPU. These processors contain logic gates that can rapidly open and close circuits. Modern processors have so many circuits and transistors, they can perform billions of instructions every second.

Updated April 22, 2016 by Per C.

quizTest Your Knowledge

A file association describes the relationship between a file type and what?

A folder that contains files of that type
The default program that opens that file type
The maximum file size for that file type
Which user accounts have permission to open that file type
Correct! Incorrect!     View the File Association definition.
More Quizzes →

The Tech Terms Computer Dictionary

The definition of Circuit on this page is an original definition written by the team. If you would like to reference this page or cite this definition, please use the green citation links above.

The goal of is to explain computer terminology in a way that is easy to understand. We strive for simplicity and accuracy with every definition we publish. If you have feedback about this definition or would like to suggest a new technical term, please contact us.

Sign up for the free TechTerms Newsletter

How often would you like to receive an email?

You can unsubscribe or change your frequency setting at any time using the links available in each email.

Questions? Please contact us.