Link to this headingTransistor

Gate: When voltage is supplied this is that switches the transistor on and off

N Channel: will flow voltage from Source (Voltage) to Drain (Load)
P Channel: will flow voltage from Drain to Source

Link to this headingMetal Oxide Semiconductor FETs (MOSFET)

Output is biased off of the input voltage

Link to this headingBJT (Bipolar Junction Transistor)

Emitter: output voltage
Base: low voltage switch input
Collector: input voltage

A small current at the base terminal flows between the base and the emitter, This switches a much larger current between the collector and emitter.

Link to this headingFET (Field Effect Transistor)

A voltage at the gate can control a current between source and drain