Noun

Singular switch

Plural switches

switch (plural switches)

1. A device to turn electric current on and off or direct its flow.
2. (rail transport, US) A movable section of railroad track which allows the train to be directed down one of two destination tracks; point.
3. A slender woody plant stem used as a whip.
4. (computer science) A command line notation allowing specification of optional behavior.
5. (computer networks) A networking device connecting multiple wires, allowing them to communicate simultaneously, when possible. Compare to the less efficient hub device that solely duplicates network packets to each wire.
6. (telecommunications) A system of specialized relays, computer hardware, or other equipment which allows the interconnection of a calling party's telephone line with any called party's line.
7. (BDSM) One who is willing to take either a sadistic or a masochistic role.

Synonyms

• (section of railroad track): (UK) points
• (whip): crop
• (Computer Science): flag, option, specifier

Derived terms

• light switch

In electronics, a switch is an electrical component that can break an electrical circuit, interrupting the current or diverting it from one conductor to another. The most familiar form of switch is a manually operated electromechanical device with one or more sets of electrical contacts. Each set of contacts can be in one of two states: either 'closed' meaning the contacts are touching and electricity can flow between them, or 'open', meaning the contacts are separated and nonconducting.

A switch may be directly manipulated by a human as a control signal to a system, such as a computer keyboard button, or to control power flow in a circuit, such as a light switch. Automatically-operated switches can be used to control the motions of machines, for example, to indicate that a garage door has reached its full open position or that a machine tool is in a position to accept another workpiece. Switches may be operated by process variables such as pressure, temperature, flow, current, voltage, and force, acting as sensors in a process and used to automatically control a system. For example, a thermostat is an automatically-operated switch used to control a heating process. A switch that is operated by another electrical circuit is called a relay. Large switches may be remotely operated by a motor drive mechanism. Some switches are used to isolate electric power from a system, providing a visible point of isolation that can be pad-locked if necessary to prevent accidental operation of a machine during maintenance, or to prevent electric shock.