In electronic components, Active components are electronic devices that need an external power source to operate actively.  They mainly manipulate, amplify, switch, or control the flow of electric current or voltage in a circuit.  Active components, like diodes, transistors, integrated circuits (ICs), and sensors require power to do their job.  A circuit is an interconnection of components.  These components are capable of performing active functions like amplification, rectification, and switching they are called active components.