At one time, the only computing devices available were enormous machines of the type we now think of as mainframe computers. Over time, smaller computers, known as minicomputers, were introduced, though these were still the size of a large bookcase or cabinet. When computers small enough to fit on a desk were introduced, they were referred to as microcomputers.
Desktop Microcomputer Definition
Almost all the computers that average people interact with today are microcomputers. The term is somewhat old-fashioned and not commonly used in advertising or industry literature.
A microcomputer usually has a single main processing chip or central processing unit. They're smaller than mainframe computers, which dominate a reasonably sized room, and minicomputers, which may be as tall as a refrigerator.
Microcomputers originally were less powerful and substantially cheaper than the larger alternatives, but they've grown substantially more powerful and gone on to dominate the computing market. Microcomputers were the first computers that were both affordable and practical to be installed in a home or small business.
Desktop and laptop computers commonly found in offices and homes are microcomputers. Smart phones and personal digital assistants can also be considered microcomputers, although the term isn't commonly used to describe them.
Some people use "microcomputer" and "personal computer," or "PC," interchangeably, although PC is also used to describe a computer running a Microsoft operating system, similar to the original IBM PC introduced in the 1980s.
Types of Microcomputer
Some common microcomputer examples include modern-day Windows and Mac computers, which dominate the market. All desktops and laptops commonly sold in office supply stores are microcomputers. Many servers in use in commercial data centers are also microcomputers.
Microcomputers can run a variety of operating systems, including Microsoft Windows, Apple macOS and various distributions of Linux. Older microcomputers included the Commodore 64 and Amiga, Tandy devices from Radio Shack, and early Apple products such as the Apple II and Lisa computers.
It's possible for a single person to lift a microcomputer, and the devices typically don't require any special cooling or electrical hardware to operate.
Alternate Definitions of Microcomputer
In some cases, the term "microcomputer" refers to a smaller computer than it originally invoked. The term is also used to refer to a tiny computer found embedded in another device, like a smart appliance.
Since the term microcomputer isn't widely used in common conversation and can have more than one definition, it's probably best to define it when using it in informal speech or writing.