There are many kinds of circuit

• An electric circuit interconnects electrical elements. Examples in electronics include
  • printed circuits
  • integrated circuits
  • digital circuits
  • Series and parallel circuits
  • Telecommunication circuits
• A sport circuit is a closed, often oval or circular, racing track used for motor sports, track cycling, running, skating etc.
• Some political and judicial administrative divisions are known as Circuits.
• At an airfield, the circuit is an agreed pattern for managing local air traffic.
• In mathematics, a circuit can refer to
  • a closed walk in graph theory
  • a minimal dependent set in combinatorics