A metrical foot (aka poetic foot) is the basic repeating rhythmic unit that forms part of a line of verse in most Indo-European traditions of poetry.
In some metres (such as the iambic trimeter) the lines are divided into double feet, called metra (singular: metron).
In a poetic composition, a verse is formally a single metrical line.
A rhyme is the repetition of syllables, typically found at the end of a verse line.
A stanza is a group of lines forming the basic recurring metrical unit in a poem.