A switch has two primary states:

• Open: When the switch is open, the circuit is incomplete, preventing current from flowing. This is equivalent to turning the switch "off."
• Closed: When the switch is closed, it completes the circuit, allowing current to flow through it. This is equivalent to turning the switch "on."

Types of Switches:

• Single-Pole Single-Throw (SPST): The simplest type of switch with one input and one output. It connects or disconnects a single path.
• Single-Pole Double-Throw (SPDT): Has one input and two outputs, allowing the current to be switched between two different paths.
• Double-Pole Single-Throw (DPST): Contains two switches operated by a single mechanism, controlling two separate circuits simultaneously.
• Double-Pole Double-Throw (DPDT): Essentially two SPDT switches that operate together, allowing control of four different paths.