What is the origin of the idiom "ad hoc" and when to use it?

The idiom "ad hoc" originates from Latin, where "ad" means "to" or "for" and "hoc" means "this." It is used to describe something that is created, organized, or done specifically for a particular purpose or situation, rather than being part of a pre-established plan or system. The idiom conveys the idea of something being temporary, improvised, or designed to address an immediate need or circumstance.