Electronic components are any physical entity in electronic systems used to affect the electrons or their associated fields in a desired manner consistent with the intended function of the electronic system. Components are generally intended to be connected together, usually by being soldered to a printed circuit board (PCB), to create an electronic circuit with a particular function (such as an amplifier, radio receiver, or oscillator). Components may be packaged singly or in more complex groups as integrated circuits. Some common electronic components are inductors, resistors, diodes, capacitors, transistors, and so on. Components are often categorized as active or passive.