The basic definition of rhyme is two words that sound alike. The vowel sound of two words is the same, but the initial consonant sound is different. Rhyme is perhaps the most recognizable convention of poetry, but its function is often overlooked. Rhyme helps to unify a poem; it also repeats a sound that links one concept to another, thus helping to determine the structure of a poem. When two subsequent lines rhyme, it is likely that they are thematically linked, or that the next set of rhymed lines signifies a slight departure. Especially in modern poetry, for which conventions aren't as rigidly determined as they were during the English Renaissance or in the eighteenth century, rhyme can indicate a poetic theme or the willingness to structure a subject that seems otherwise chaotic. Rhyme works closely with meter in this regard. There are varieties of rhyme: internal rhyme functions within a line of poetry, for example, while the more common end rhyme occurs at the end of the line and at the end of some other line, usually within the same stanza if not in subsequent lines. There are true rhymes (bear, care) and slant rhymes (lying, mine). There are also a number of predetermined rhyme schemes associated with different forms of poetry. Once you have identified a rhyme scheme, examine it closely to determine (1) how rigid it is, (2) how closely it conforms to a predetermined rhyme scheme (such as a sestina), and especially (3) what function it serves.