The invention of the integrated circuits (ICs), also known as microchips, paved the way for computers as we know them today. Making circuits out of single pieces of silicon, which is a semiconductor, allowed them to be much smaller and more practical to produce. This also started the ongoing process of integrating an ever larger number of transistors onto a single microchip. During the sixties microchips started making their way into computers, but the process was gradual, and second generation of computers still held on.
First appeared minicomputers, first of which were still based on non-microchip transistors, and later versions of which were hybrids, being based on both transistors and microchips, such as IBM’s System/360. They were much smaller, and cheaper than first and second generation of computers, also known as mainframes. Minicomputers can be seen as a bridge between mainframes and microcomputers, which came later as the proliferation of microchips in computers grew.