Final answer:
A rhyming couplet consists of two lines that end in rhyme and is a common feature in English poetry, including classical heroic couplets as well as modern variations like split couplets.
Step-by-step explanation:
A rhyming couplet is a pair of lines where the end words rhyme with each other. This is a popular form in English poetry and can be found across different eras, from the work of writers in the 17th and 18th centuries like Alexander Pope, who oftentimes employed heroic couplets, to modern poets. A heroic couplet is composed of iambic pentameter lines, which was particularly popular in the neoclassical period of literature.
An example from Pope's An Essay on Criticism wonderfully illustrates the use of the couplet rhyme scheme. Similarly, Shakespeare's sonnets frequently end with a couplet, providing a summing up or a twist in the concluding lines. While couplets were traditionally formatted in formal verse, they can also appear in free verse, where poets might use internal rhymes or more relaxed patterns.
In addition to these traditional forms, variations like the split couplet exist, combining lines of differing lengths, usually with the first line in iambic pentameter and the second in iambic dimeter.