What is meant by ownership and possession of a property?

[Jurisprudence] Ownership is the fullest right that can exist over a thing, and must of necessity be over one’s own property. In other words, it is a jus in re propria. The right to possess, however, may or may not exist over one’s own property. Thus, a person may be a lessee of someone else’s property but during the lease his is the right to another’s property. The right of security, for example, is invariably over another’s property, so is an easement. What is to be noted is that ownership is always a right in re propria possession may be a jus in re propria or in aliena, while rights such as security and easement can only be jura in re aliena.