You only own a leasehold property for a fixed period of time.
You’ll have a legal agreement with the landlord (sometimes known as the ‘freeholder’) called a ‘lease’. This tells you how many years you’ll own the property.
Ownership of the property returns to the landlord when the lease comes to an end.
Most flats are leasehold. Houses can be leasehold too and usually are if they’re bought through a shared ownership scheme.