Freehold means you own the building and the land it stands on outright. Leasehold means you own the right to occupy it for a set number of years while a freeholder retains the land. Most houses are freehold and most flats are leasehold. With leasehold your solicitor checks the remaining lease length, ground rent, service charges and any restrictions written into the lease. A short lease affects both your mortgage and your ability to sell on, so it is worth asking about early when looking at flats.