Rhyme is a particular form of assonance in poetry, in which the syllable at the end of one line has the same or similar sound as the syllable at the end of another. If the line ends on an unstressed syllable, then both the stressed syllable preceding it and the following syllable(s) should have the same sound. Different languages have different rules for deciding whether a rhyme is "correct". In English, it is not considered correct if the consonant (or combination of consonants) with which the rhyming syllables begin is the same. French, for example, has no such objection.
An eye-rhyme occurs when a syllable appears to have the same ending on paper, but actually sounds differently.
Internal rhyme is when the end of a half-line ends with the same sound as the end of the line itself. The device is much used in ballads.
In imperfect rhyme the two rhyming syllables have enough in common (usually the vowel sound) for the assonance to be recognisable without being identical.
A rhyme scheme is a particular rule for combining rhymes in a verse form or stanza.
A masculine rhyme ends on a stressed syllable, whereas a feminine rhyme includes a stressed syllable, but ends on an unstressed one. Thus remark rhymed with embark is a masculine rhyme, while marker rhymed with darker is a feminine one. Ingenious or complex feminine rhymes are often used in comic verse.
In Europe, rhyme was unknown in classical poetry and also in the alliterative verse of the north, but became popular as a poetic effect in the Middle Ages. Geoffrey Chaucer was the first major poet to use rhyme in English, establishing it as normal in place of alliterative verse.