Land is important; who owns a piece of land determines what to do with its mineral and water rights as well as how it gets developed, such as for residential, commercial, or farming purposes. Due to this most countries have a very strict land tenure system to determine who owns a particular piece of land.
Most tenure systems break down to some form of private and public ownership. Public ownership is both for land set aside for conservation and enjoyment, such as parks, as well as communally owned areas farmed by everyone. Private ownership is for how individuals and companies may develop the land. They are even some hybrid systems such as sharecropping, where a group of people shares ownership of a plot of land.
By enforcing these systems a number of issues are solved, allowing the community to better use the land to the benefit of all.