Electric field
From Computer History Wiki
The electric field is one of the five fundamental fields that pervade space, along with magnetic, strong, weak and gravitational fields - although electricity and magnetism have been considered two aspects of one more fundamental field since the late 1800's.
At every point in space, the electric field has a value which is a vector, i.e. a strength and a direction.
The electric field can exert a force on a charged entity, such as an electron. This effect is used in many ways, including in semiconductor devices of all kinds, and in CRTs (which use beams of electrons).