A stanza is a related group of lines or verses in a poem. A stanza also can be a verse in paragraph form. They can keep on going without punctuation. It may also be a line poem.
Two most important features of a stanza is the number of lines and the rhyme scheme. There are many kinds of stanza.
An Italian sonnet consists of two four-line stanzas and two three-line stanzas:
A French ballad is composed of three eight-line stanzas and a four-line one:
Some stanzas are named after poets, who invented or often used them. An example is Sapphic stanza that was named after famous Greek woman poet Sappho.