Logic is a set of rules which describe the function of the digital circuit. The digital circuit is made of transistors that switch on or off based on how they are oriented in the circuit. They themselves make no decision. Integrated circuits (ICs) are built of logic gates. These logic gates also form flip-flops, which store data in bytes. Logic gates are made up of transistors, usually MOSFETs (a kind of field effect transistor). So, transistors make logic gates make flip-flops make registers and other data storage units. logic gate (AND, OR, XOR, NOT, NAND, NOR and XNOR)