Nanowire transistor
Beginner
A transistor whose channel is a very thin wire with the gate wrapped all around it. It turns off well but carries little current.
Novice
A gate-all-around transistor whose channels are thin round or square wires, a few nanometers across. The gate controls them very well, but each wire carries little current, and adding wires adds capacitance.
Expert
GAA with channels of similar width and thickness. Best electrostatics per channel but small per footprint, which is why industry moved to wider, flat nanosheets.
Explained in Fins and nanosheets (Transistors).
See also: Gate-all-around (GAA) nanosheet, Effective width (W_eff).