Leasehold is a legal status where a tenant is registered as having a legal interest in a property and does not own the property. This happens in long term commercial leases and at times in long term residential leases as well.
Leasehold allows tenants a greater set of laws that protect them. For instance, there are limited reasons why a landlord can end a leasehold early. If the landlord succeeds, the amount of notice allowed to the tenant is greatly increased under leasehold terms.