Lines whose rhythm depends on the duration or length of time a line takes to utter. That duration depends on whether a syllable is long or short. Edmund Spenser's "Iambicum Trimetrum" is an example of trying to adapt, in English, a metre natural to Greek and Latin.

These are four line verse poems. The lines can rhyme in two patterns. Lines one and two and three and four or lines one and three.
Example by British poet laureate, Andrew Motion, "Causa Belli" —

"They read good books, and quote, but never learn
a language other than the scream of rocket-burn.
Our straighter talk is drowned but ironclad:
elections, money, empire, oil and Dad."

A five-line stanza, such as a limerick or Edmund Waller's "Go, lovely Rose." Also called a cinquain.