There are "PNP" and "NPN" varieties of both.

BJT:
Current-controlled
Can be turned "partially on"
Constant, linear power loss while conducting

FET:
Voltage-controlled
ON or OFF
Power loss during switching; minimal while on
RDS(on) is typically <1ohm

There are "PNP" and "NPN" varieties of both.

BJT:
Current-controlled
Can be turned "partially on"
Constant, linear power loss while conducting

FET:
Voltage-controlled
ON or OFF
Power loss during switching; minimal while on
RDS(on) typically measured in mOhm's