Car hire is the term given to the short term rental of a car. You can rent or hire a car for as long as you like. However, with most companies you must rent a car for at least a day. If you decide to give the car back on the same day, some car hire companies may offer a small refund on the cost.
Car hire is getting cheaper in the UK, and many car hire companies allow you to take a car from one location, and drop it off at another location in the UK within the same price.