it is a single chip microcomputer consisting of a memory unit and an i/o unit
Microcontroller A microcontroller (MCU for microcontroller unit, or UC for Î¼-controller) is a small computer on a single integrated circuit. In modern terminology, it is similar to, but less sophisticated than, a system on a chip or SoC; an SoC may include a microcontroller as one of its components. A microcontroller contains one or more CPUs (processor cores) along with memory and programmable input/output peripherals. Program memory in the form of ferroelectric RAM, NOR flash or OTP ROM is also often included on chip, as well as a small amount of RAM. Microcontrollers are designed for embedded applications, in contrast to the microprocessors used in personal computers or other general purpose applications consisting of various discrete chips.
Computer data storage In contemporary usage, "memory" is usually semiconductor storage read-write random-access memory, typically DRAM (dynamic RAM) or other forms of fast but temporary storage. "Storage" consists of storage devices and their media not directly accessible by the CPU (secondary or tertiary storage), typically hard disk drives, optical disc drives, and other devices slower than RAM but non-volatile (retaining contents when powered down).[2]