Plug-in
In Logic Pro for Mac, plug-ins are generally software instruments or effects that are “plugged into” their respective channel strip slot. They appear in their own plug-in window, floating on top of the Logic Pro for Mac interface.
Logic Pro for Mac features a large collection of built-in effect and instrument plug-ins. It also supports plug-ins from manufacturers other than Apple in the Audio Units format.
Plug-ins can be broken down into the following categories:
Audio effect plug-ins: Can be inserted in Audio Effect slots on audio, instrument, aux, or output channel strips.
MIDI effect plug-ins: Can be inserted only in MIDI Effect slots on instrument channel strips.
Software instrument plug-ins: Can be inserted only in the Instrument slot on instrument channel strips.