Original: A microcontroller (sometimes abbreviated Â C, uC or MCU) is a small computer on a single integrated circuit containing a processor core, memory, and programmable input\/output peripherals.
Simplified: A microcontroller (abbreviated MCU or Â C) is a high integrated functional computer system-on-a-chip. It contains an integrated processor core, memory (a small amount of RAM, program memory, or both), and programmable input\/output peripherals.