Electrification refers to changing a thing or system to operate using electricity. A more specific usage of the word refers to the act or process of building the necessary infrastructure to supply electric power to homes and businesses, especially in rural and isolated areas or the changeover of a railway from in the past steam locomotives, but now most often diesel-powered locomotives to electric locomotives. The infrastructure required for electrification includes power plants, long haul transmission lines, substations and shorter transmission lines to the end user.