Microcontroller USUALLY operates at frequencies in MHz range while today's Microprocessor operates in GHz frequency range. This clock is provided using oscillator. Microcontroller and microprocessor both have their own applications. Hence both cannot be USED for each other's functional areas except for few exceptions (very low size code/data application).
In ADDITION to microprocessor (CPU) functionality microcontroller will have timers, counters, RAM, ROM and Input/Output ports. Most of the microprocessors have Op-codes for moving data from the external memory to the CPU; Microcontrollers may have one or two. Microprocessors have one/two types of bit HANDLING instructions while Micro controllers have many. Microprocessor is used for general PURPOSE applications while microcontroller is program specific and designed for particular application in consideration.

Microcontroller usually operates at frequencies in MHz range while today's Microprocessor operates in GHz frequency range. This clock is provided using oscillator. Microcontroller and microprocessor both have their own applications. Hence both cannot be used for each other's functional areas except for few exceptions (very low size code/data application).
In addition to microprocessor (CPU) functionality microcontroller will have timers, counters, RAM, ROM and Input/Output ports. Most of the microprocessors have Op-codes for moving data from the external memory to the CPU; Microcontrollers may have one or two. Microprocessors have one/two types of bit handling instructions while Micro controllers have many. Microprocessor is used for general purpose applications while microcontroller is program specific and designed for particular application in consideration.