Leasehold title is a valid type of land “ownership”. Think of a land leasehold agreement as an alternative to renting (leasing) and full ownership (freehold title).
Leasehold title is not full ownership. Leasehold generally relates to control of the land.
For properties controlled leasehold by the owner, the land is leased (generally on a long-dated lease), and the top structures or buildings are owned.
A leasehold agreement allows the leaseholder the right to use and enjoy defined real estate for the period of the leasehold agreement (99 years, for example). This might include activities such as adding to it / developing top structures on it, sub-letting the property, or renovating it (rights not usually granted in a lease but which are indicative of freehold title). The leaseholder is not the owner of the leased property during the leasehold period. After the period is up, any improvements the leaseholder made to the property become the property of the owner.
Leaseholders can, for example, sometimes raise finance on the property using the leasehold agreement as security for a mortgage bond, both of which can be appended to the title deed.
Why pursue leasehold title, rather than freehold title or renting? Think of it as having some of the benefits of freehold title without a large initial capital outlay. The two factors supporting leasehold: a) a 99 year lease is longer than most lifetimes, and b) the property will change ownership a couple times, long before the land lease expiry becomes an issue.