Short answers, pulled from the story.
Metre in poetry is the basic rhythmic structure of a verse or lines in verse. It organizes syllables into patterns based on stress, syllable weight, or syllable count, depending on the language and tradition. The study and use of metres and versification forms is called prosody.
Qualitative metre, common in English poetry, patterns syllables by stress, with stressed syllables arriving at regular intervals. Quantitative metre, used in Classical Latin, Classical Greek, and Sanskrit, patterns syllables by weight or duration, distinguishing long syllables from short ones regardless of stress. English iambic pentameter is qualitative; Homeric dactylic hexameter is quantitative.
Iambic pentameter is the most frequently encountered metre in English verse, built from five iambic feet per line, each foot consisting of an unstressed syllable followed by a stressed one. John Milton used it throughout Paradise Lost, Shakespeare used it extensively in his plays as blank verse, and Wordsworth used it in The Prelude. Unrhymed iambic pentameter is called blank verse.
Al-Farahidi, who lived from 718 to 786 CE, was the first scholar to subject Arabic poetry to systematic metrical analysis. His first book, al-Ardh, described fifteen types of verse; a sixteenth was later added by Al-Akhfash. Classical Arabic has sixteen established metres in total.
The dactylic hexameter is a line of six feet used in Homer's epics and Virgil's Aeneid, making it the most important metre of the classical world. Each line pairs dactyls with spondees across its six feet, with the fifth foot being almost always a dactyl. Henry Wadsworth Longfellow imitated the form in English in his poem Evangeline.
Sprung rhythm is a metrical innovation developed by Gerard Manley Hopkins. It organizes feet around a variable number of syllables, generally between one and four, with the stress always falling on the first syllable of each foot. Hopkins argued this approach freed poetry from the inherited two-or-three syllable repeating groups that dominated the English tradition.