Integrated circuits are tiny electronic circuits built to perform a particular function made of active and passive components such as transistors, field-effect transistors, diodes, resistors, capacitors, etc.
Before the invention of transistors, vacuum tubes were used. The main drawback of vacuum tubes was their size. Transistors reduced the size of circuits substantially, but still the circuits were bulky. Gordon Moore, a co-founder of Intel, had predicted that the number of transistors placed on the chip would double every two years. For every added function to circuit, the components added were almost double.
I HOPE IT WILL HELP U!