https://en.wikipedia.org/wiki/Preposition_and_postposition
Prepositions and postpositions, together called adpositions (or broadly, in traditional grammar, simply prepositions), are a class of words used to express spatial or temporal relations (in, under, towards, before) or mark various semantic roles (of, for).. A preposition or postposition typically combines with a noun phrase, this being called its complement, or sometimes object.