I have this gift that was given to me as a present for my birthday, but was informed that is not mine permanently but to keep until my friend wants it back. What is that kind of gift called?
This is often referred to as a permanent loan
A form of loan agreement in which an individual, trust, or company loans artwork or other objects to a museum for an extended period of time. The loan agreement may stipulate that the museum must display the loaned artwork in a specific area of the museum, that the artwork is to be displayed as part of an exhibition, or that the artwork is not to be shown in a touring exhibition.
Despite the word permanent in this phrase, such loans are not necessarily that:
Accepting artwork under a permanent loan does put a museum at a risk, however. While the word “permanent” is used to describe the time period of the loan, objects loaned under this sort of agreement can still be withdrawn at any time. For example, the heirs of a wealthy collector may request a painting be returned.