Difference between a mini computer and micro computer?

One difference between microcomputers and minicomputers is their relative size. A minicomputer would describe a server-class machine, meaning a computer with possibly several processors working in tandem, while a microcomputer would describe your average desktop or laptop with a single microprocessor.

Another possible point of comparison would be performance. A minicomputer could describe a very high-end system (e.g. technical workstations like the SGI graphics renderer) capable of doing highly specific and complex tasks, while a microcomputer would describe your basic calculator or PC, which would probably gag at the thought of doing the task of a minicomputer, but would be able to process several high-level languages (e.g. C++, VB, Pascal) and turn them into machine-level language for execution, unlike a majority of minicomputers, which is created such that there is a very tight integration between hardware and software.