Types of rhyme scheme include rhyming couplets, alternate-line rhyme schemes and sonnet rhyme schemes. The term "rhyme scheme" refers to the pattern of rhyming lines in a poem and is identified by letters to indicate which lines rhyme.
A rhyming couplet is the most common type of rhyme scheme. A couplet is a two-line stanza in a poem or song. If the two lines rhyme, they have an aa rhyme scheme. If two lines in the next couplet rhyme, they have a bb rhyme scheme.
In an alternate-line rhyme scheme, every other line in a stanza rhymes. For example, an abab rhyme scheme refers to a four-line stanza in which the first and third lines rhyme as do the second and fourth lines. In a stanza containing an abcb rhyme scheme, only the second and fourth lines rhyme.
A sonnet is a type of poem with 14 lines that follow a specified rhyming scheme. In an Italian sonnet, the first eight lines follow an abba abba rhyme scheme, and the last six follow a cde cde or cdc cdc rhyme scheme. In an Elizabethan, or Shakespearean sonnet, the rhyme scheme is abab cdcd efef gg, while a Spenserian sonnet uses an abab bcbc cdcd ee rhyme scheme.