Microcontrollers vs. Microprocessors

Yes, and no. How's that for an answer?

Microprocessors and microcontrollers are designed for specific tasks. However, generally, a microprocessor is designed for high speed computational jobs that use lots of memory and require high speed calculations. To do this they generally use more power and generate more heat. Microprocessors tend to cost much more than microcontrollers.

Microcontrollers are geared for more input/output tasks. If you look at the applications for microcontrollers they are heavily involved with reading hardware inputs (either discrete or analog), making decisions based on the state of those inputs, and then driving outputs to a desired state.

Microcontrollers tend to be very miserly in power requirements. To do this microcontrollers tend not to have the memory management units, math coprocessors, external memory address and data lines, nor the clock speed. For example, a microcontroller might run at 20 MHz. Your PC might run at 3 GHz!

So, microcontrollers tend to get rid of any unused baggage that a typical microprocessor has by default. In its place they tend to put lots of input and output ports on the microcontroller and specialized pins for driving or reading the external world.

Another critical difference is package size. Microprocessors tend to be very big and have hundreds of pins (mostly address and data lines). Microcontrollers can typically have as few as 8 pins.

There are all kinds of variants that exist in between these two extremes. So, when designing for an application you can spend a lot of time searching and picking one that has all the features you need and no extra features you don't need.