What A Wire Actually Is
A wire is usually a thin piece of metal like copper which is a lattice of fixed positive atomic cores (nuclei + inner electrons). This lattice is made up of atomic nuclei which are positively charged atoms which are arranged in a 3D repeating crystal pattern (lattice). Electrons slowly drift along the wire because of something called voltage. Voltage (difference in energy) is basically just how much a charge would "want" to move from one place to another in simple terms.
Sense the electrons naturally move to lower charged areas, this movement then goes to your device you are trying to charge.