Electronic components, which are the basic elements in electronic circuits, are usually individual packages and have two or more leads or metal contacts. The electronic components must be interconnected to form an electronic circuit with a specific function, such as an amplifier, a radio receiver, an oscillator, etc. One of the common ways of connecting electronic components is soldering to a printed circuit board. Electronic components may be separate packages (resistors, capacitors, inductors, transistors, diodes, etc.) or groups of different complexity, such as integrated circuits (operating amplifiers, resistors, logic gates, etc.).