Electronics is a branch of science that deals with the use and manipulation of electric currents. It differs from the science of electricity because it considers current not only as a form of energy but also as a means of conveying information. This information may take the form of sound, pictures, numbers or letters and is transmitted through devices that vary or change a current's behaviour. Such devices are called electronic signals and they can serve many purposes, such as allowing doctors to see images of bones or other parts of the body, diagnosing fractures, detecting poisons in the body, or transmitting x-ray images through materials to show what they look like inside.
Electronic equipment grew increasingly sophisticated during the 1920s and 1930s. Engineers began to make better vacuum tubes, such as the three-electrode tube known as the triode tube. This made possible inventions such as television and films with sound. Engineers also invented a device that produced microwaves for radar. This led to the development of microwave ovens and other home products.
The field of industrial electronics, which is oriented towards manufacturing products required by modem industry such as numerically controlled machinery and robots, also depends on electronic technology. In addition, the field of medical electronics is dependent on electronic technology since it makes possible such devices as ECG recorders and nuclear magnetic resonance scanners. It also contributes to computer technology by making it possible to design integrated circuits that are smaller and faster than those used in conventional equipment.
