Single-chip microcomputer is a digital computer built on a single IC chip. It is also called micro controller. It has become possible with advancements is VLSI and VLSI technologies.
These are used in applications such as instrumentation, automatic industrial control, process control, commercial and home appliances etc.
It contains all components of a microcomputer such as CPU, RAM, ROM/EPROM/I/O lines etc. We have 16-bit ans 32 bit micro controllers made by different companies with different features.