a people or nation: a distinct body of people forming one ethnic or political group; a lofty, poetic word, most often used in the plural ("peoples")
This is a poetic, elevated word for a people or nation. In everyday Hebrew prose the ordinary words are "people" and "nation"; this word belongs instead to the language of psalms, prophecy, and blessing, where it stands beside those two words in matched poetic lines.
It appears overwhelmingly in the plural, "peoples," picturing the many nations of the earth in a single sweep. In that setting it names them as those God rules and judges, as witnesses summoned to listen to him, or as peoples who will one day praise him. Now and then it names a single people instead, whether a foreign nation or God's own.
Whether it points to the whole crowd of the world's peoples or to one nation among them, the word carries the same idea: a community large enough to count as a people in its own right. The two senses differ only in scope, not in kind.