Very-Large-Scale Integration

The first semiconductor chips held one transistor each. Subsequent advances added more and more transistors, and as a consequence more individual functions or systems were integrated over time. The microprocessor is a VLSI device.

The first "generation" of computers relied on vacuum tubes. Then came discrete semiconductor devices, followed by integrated circuits. ICs had more than one device on a single chip - diodes, transistors, resistors and capacitors (no inductors though), making it possible to fabricate one or more logic gates on a single device. The fourth generation consisted of Large-Scale Integration, i.e. systems with at least a hundred logic gates. The natural successor to LSI was VLSI (thousands of gates on a single chip). Current technology has moved far past this mark and today's microprocessors have several million gates.