You need a cable and an electricity supply. Most electric cars can be charged at home by simply plugging into a standard British 13amp socket, using a cable which comes with the car. It really is as easy as charging your phone. Faster sockets, commonly "Type 2' outlets, can be installed at home or work; often for free or cheaply with support from Government Grants.
Away from home, public chargers are available up and down the country, and there are currently over 30,000 available. Public charge points can offer much faster speeds than those available at home, assuring a full charge for a vehicle whilst taking a short stop break on a long journey.