The movement of electrons inside a conductor is called electric current. When the electrons move along in the same direction, it is called direct current.
To create a direct current in a wire one needs a battery. The positive terminal of the battery is connected to one side of the conductor (cable) and the negative to the other side, the electrons flow through the cable.

An electric current can have different intensities.

The intensity of the current is a way to measure the quantity of electrons that move along the cable.

The charge transported by the electrons through the cross section (S) of the conductor per second is called current or intensity of the current (I = charge / second)