Discrete devices encompass a broad range of electrical components used in a circuit or system.  It is used to separate the components that are built into a base surface by the process of deposition or integration, like many semiconductor integrated circuits that form and emerge from the base layer as opposed to being placed there separately.  On the other hand, discrete devices are separate components that require some form of joining or union with the overall system before their contribution can be made.  Usually for PCBs discrete components are soldered or crimped onto the board.

Some examples of discrete components are capacitors, resistors, BJT and MOSFET transistors, jumper wires, other joining wiring, operational amplifiers, inductors, amplifiers and antennas.