The units of poetic meter, like rhyme, vary from language to language and between poetic traditions. They can involve arrangements of syllables into repeated patterns called feet within a line. English meter is founded on the patterns of stressed and unstressed syllables. In Latin and Greek verse, on the other hand, while the metrical units are similar, not syllable stresses but syllable lengths are the component parts of meter.
Meter (poetry) Facts for Kids. Kiddle Encyclopedia.