a debugger is for debugging the system.
you can monitor the signals at any point but more in an user friendly way.
an emulator is used as a substitute for the main controller or eprom(rom) etc..
and you can control the ucontroller in any way.
it can debug at ucontroller hw level.
whereas a debugger is for external signal debugging only.
both 'debugger' and 'emulator ' are explained with hardware as reference.
there exists a software 'debugger ' and softaware 'emulator(simulator)' which is notmentioned here.
srizbf
3rdmay2010