The field of Electronics is a branch of physics and electrical engineering that deals with the emission, behaviour and effects of electrons using electronic devices. Electronics uses active devices to control electron flow by amplification and rectification, which distinguishes it from classical electrical engineering, which only uses passive effects such as resistance, capacitance and inductance to control electric current flow.
Electronics has hugely influenced the development of modern society. The identification of the electron in 1897, along with the subsequent invention of the vacuum tube which could amplify and rectify small electrical signals, inaugurated the field of electronics and the electron age. Practical applications started with the invention of the diode by Ambrose Fleming and the triode by Lee De Forest in the early 1900s, which made the detection of small electrical voltages such as radio signals from an radio antenna possible with a non-mechanical device. The growth of electronics was rapid, and by the early 1920s commercial radio broadcasting and communications were becoming widespread, and electronic amplifiers were being used in such diverse applications as long distance telephony and the music recording industry.
The next big technological step took several decades to appear, when Solid-state electronics emerged with the first working semiconductor transistor which was invented by William Shockley, Walter Houser Brattain and John Bardeen in 1947. The vacuum tube was no longer the only means of controlling electron flow. The MOSFET (MOS transistor) was subsequently invented in 1959, and was the first compact transistor that could be miniaturised and mass-produced. This played a key role in the emergence of microelectronics and the Digital Revolution. Today, electronic devices are universally used in Computers, telecommunications and signal processing employing Integrated circuits with sometimes millions of transistors on a single chip