A Triplet, as in:
Do not go gentle into that good night.
Old age should burn and rave at close of day,
Rage, Rage against the dying of the light.
The poem is made up of 5 triplets (such as this, the first one in rhyme scheme aba) and a quatrain at the end (four-line stanza, rhyme scheme abab).
A stanza of four lines is called a quatrain.
a stanza with 5 lines is called a sestet
A stanza with two lines is called a couplet.
A stanza of two lines is called a couplet.
Every Four lines in any poem is called a ''Stanza''.
A stanza of two lines is called a couplet.
A miscellaneous 8 line stanza is called an octet. But the 8 line stanza which forms the first verse of a sonnet is called an octave, and the commonest form of 8 line stanza (by far) in English is called ottava rima.
a quatrain
A four-line stanza is called a quatrain.
The lines of a poem which group together are called a verse, a stanza, or a strophe. A poem can have verses, the same as a song can: stanza and strophe are just other words for 'verse'.
A stanza or paragraph
A stanza with twenty lines is typically called a "sestet" or a "sestina." In traditional poetry forms like the sonnet or the villanelle, a sestet refers to a stanza with six lines.