In poetry, a grouped set of lines similar to a paragraph is called a stanza. Stanzas organize a poem into sections, and they are commonly separated by a blank line or indentation. The visual break often signals a shift in idea, image, speaker, setting, or emotional movement.
Some stanzas follow fixed patterns. A couplet has two lines, a tercet has three, and a quatrain has four. More elaborate forms include the Spenserian stanza, while poems such as sestinas are defined partly by the number and arrangement of their stanzas. A stanza may use regular rhyme and meter, but neither is required.
The related term “strophe” can sometimes be used similarly, although it may refer more specifically to an irregular group of lines or to structural divisions in classical poetry. “Refrain” means a repeated line or group of lines, not any grouped section. A sonnet is a complete fourteen-line poem, and meter describes rhythmic pattern rather than poetic grouping.