According to a study by The Freedonia Group, U.S. manufacturers will spend $21.4 billion on connectors, capacitors, resistors and other passive components in 2005. The sales increases can be attributed to advances in wireless and fiber optic communications, as well as an improved outlook for the defense and aerospace industries. The growing number of electronic devices in motor vehicles will also benefit sales of passive components.
A passive component does not affect the electrical signals or data that pass through it. In contrast, an active component adds intelligence in some manner to the signals or data that pass through it. For example, in networking, an active hub regenerates fading input pulses into new, strong output pulses. A passive hub is just a junction box that does not affect the passing data.