Electric field strength: a physical quantity describing the strength and direction of an electric field.

The ratio of the electric field force f to the charged electric quantity q at a point in the electric field is called the electric field strength at that point, which indicates the electric field strength there.

E=F/q

Second, the nature of the electric field mainly refers to two aspects (the nature of force and the nature of energy):

1. At a certain point in the electric field, the electric field has a strong influence on the charge placed there.

2. At a certain point in the electric field, the charge placed there has energy (i.e. electric potential energy).