Best get an easy guide from a bookshop here.
.Freehold means you own the land and the building.. Leasehold means you don't own the land but you have got the right to live there for a set period..In England and Wales, for legal reasons, nearly every flat is leasehold. The term of years (the set period) may be as long as 120 years or more. It may be only a few years, or even one year, though we normally call one year 'a rental' or 'agreement' not 'a lease'
It's important to know how many years the lease is for. If you want to buy a flat by means of a mortgage the lender may not want to lend on a flat unless there is a long time (several tens of years) left on the lease.Even if you don't that's stlil something to take into account, because the next buyers may need a mortgage. I say 'left on the lease' because the first owner may have had a lease of 99 years and lived there for twelve years. The next buyer has the remainder of that lease, so their right is for 87 years and so on.
Leeseholders of flats always have terms in the lease to say what they can and cannot do there and who pays for maintenance etc of the flat and the building it's in and how. That's reason enough to have your lawyer check everything in detail.You need to know how well the building has been maintained and whether there is the risk that you may be called upon to pay a big sum later for future or outstanding building works.Particularly with flats in blocks there are 'service charges' which each leaseholder pays every year to pay for communal lighting, daily upkeep and other shared features. These can be quite large..