An electronics component is a basic element in an electronic circuit, usually individually packaged, and has two or more leads or metal contacts. Electronic components must be connected to each other to form an electronic circuit with specific functions, such as amplifiers, radio receivers, oscillators, etc. One of the common ways to connect electronic components is to solder them to a printed circuit board. Electronic components may be individual packages (resistors, capacitors, inductors, transistors, diodes, etc.), or groups of varying complexity.