What is the meaning of Realm?

An abstract sphere of influence, real or imagined.

The domain of a certain abstraction.

A scope of operation in networking or security.

A territory or state, as ruled by a specific power, especially by a king.

An otherworldly dimension or domain — magical, ethereal, or otherwise — usually ruled or created by a mystical character.

A taxonomic rank in the phylogeny of viruses, higher than kingdoms.

Source: wiktionary.org