A more thorough explanation:

INITIUM POSSESSIONIS

Initium possessionis is a Latin term that means "the beginning of the possession." It refers to the right by which possession was first held.

For example, if someone buys a piece of land, their initium possessionis would be the moment they take physical possession of the land. This means that they have the right to hold and use the land from that moment on.

Another example would be if someone finds a lost item on the street. Their initium possessionis would be the moment they pick up the item and take possession of it. This means that they have the right to keep the item and use it as their own.

Initium possessionis is the legal concept that establishes the right to possess something from the moment of physical possession. It is important because it determines who has the right to use and control the property. In the examples given, the person who physically possesses the land or the lost item has the right to use and control it, as they have established their initium possessionis.