SP, DP, ST, DT in electronic switches
In electronic switches, SP, DP, ST, and DT refer to the number of circuits and positions a switch can control:
SP: Single pole, which means the switch controls one electrical circuit
DP: Double pole, which means the switch controls two electrical circuits
ST: Single throw, which means the switch has two positions, such as on and off
DT: Double throw, which means the switch has three positions, such as on, off, and on