It's important to realize that for most of us, electricity is a mechanism for transferring energy from one place to another. It is also, for many practical purposes, a mechanism for conversion of one form of energy to another. For example, nuclear fission at a power station heats water to create steam to drive turbines which generate electricity. At your home or factory, which may be many miles away, you convert the electricity "delivered" to you into heat, light or motive power. In short, electricity gives you "energy on tap".