If you have bought a flat, you have bought a leasehold interest. This means you have the right to live in your home for a certain period without having to pay rent, except for a small ground rent. The period is set out in your lease and is either 130 years from 1 January 1981 or if you purchased under the right to buy scheme after 1 November 2012, 125 years from the right to buy completion date. As a leaseholder you only buy the right to live in your own flat and so you also have to pay a share of the costs to upkeep and repair the building and the estate where your flat is situated. Tenants also pay their share of these costs through their rent to the council.
For an independent guide to your rights and responsibilities as a leaseholder, read the Living in Leasehold Flats guide by The Leasehold Advisory Service (LEASE).