"RHYME: The repetition of similar or duplicate sounds at regular intervals, usually the repetition of the terminal sounds of words at the end of lines of verse....

Verse has not always made use of rhymes, and some poets (eg Milton) have spoken against it; nevertheless, rhyme is one of the most persistent of poetic devices. It calls attention to the word as sound, which we enjoy form its own sake, as opposed to the word as conveyor of meaning. It also functions as a marker, signalling the end of a rhythmical unit.

When a rhythmical and rhetorical unit coincide, the rhyme reinforces their correspondence; when they do not, the rhyme establishes in the mind of the reader an interaction between them."

From a readers Guide to Literary Terms, Beckson and Ganz, Thames and Hudson 1961)

Can't say fairer than that...