Function itself

Throttle: regulate the fuel-air mixture to the combustion chambers;

Throttle lever: a control in FADEC system for selecting a desired detent as well as power setting

The aircraft’s Engine

Throttle is usually used in those aircraft equipped with carburetor type piston engine

Throttle lever is usually used in those more advanced engine with FADEC system and so no need (without) using magnetos, carburetor heat, mixture controls, and engine priming.