In poetry, a stanza (/ˈstænzə/; from Italian stanza [ˈstantsa], "room") is a grouped set of lines within a poem, usually set off from others by a blank line or indentation. Stanzas can have regular rhyme and metrical schemes, though stanzas are not strictly required to have either. There are many unique forms of stanzas. Some stanzaic forms are simple, such as four-line quatrains. Other forms are more complex, such as the Spenserian stanza. Fixed verse poems, such as sestinas, can be defined by the number and form of their stanzas. The term stanza is similar to strophe, though strophe sometimes refers to an irregular set of lines, as opposed to regular, rhymed stanzas.