Short answers, pulled from the story.
The earliest surviving evidence of rhyming is the Chinese Shi Jing, dating to around the 10th century BCE. Ancient Greek and Latin poets used rhyme only occasionally, while structural rhyme in European verse developed much later, during the Middle Ages.
A perfect rhyme requires that the final stressed vowel and all following sounds are identical in both words, as in sight and flight. A slant rhyme, also called a half rhyme or near rhyme, involves only partial phonetic similarity, such as matching only the final consonants (hand and lend) or only the vowels (shake and hate).
Scholars believe rhyme became a permanent feature of Hebrew liturgical poetry around the 4th century CE, then transferred into Syriac Christian poetry written in Aramaic, and from there into Latin and eventually all other European languages. Arabic poetry also played a direct role, as rhyming qasidas entered European verse through Al Andalus, the Arabic name for modern Spain, during the High Middle Ages.
In his preface to Paradise Lost, John Milton called rhyme "the Invention of a barbarous Age, to set off wretched matter and lame Meeter." He chose to write the epic without rhyme, aligning his practice with Homer in Greek and Virgil in Latin.
A holorime is an extreme form of rhyme in which two entire lines sound nearly or wholly identical. Alphonse Allais was a notable exponent of holorime, and an example of a holorime couplet is also attributed to Marc Monnier.
French poetry prizes identical rhymes, where both the vowel sounds and the onset consonants of the rhyming syllables match, while English poets generally regard such pairs as weak or inferior. Classical French versification also classifies rhymes into four grades from rime pauvre to rime richissime, and treats the silent mute 'e' as an integral part of the rhyme.