To understand the information that follows on the characteristics of various forms, it is necessary to be familiar with a few basic terms and concepts. These are covered briefly here; anyone already familiar with them is encouraged to skip directly to the descriptions of the forms.

Rhyme, the Rhyme Scheme, and Refrains: Rhyme (the repetition of words ending with similar sounds) is a concept with which most of us are familiar. The "rhyme scheme" for a given poetic form is simply a diagram showing which lines rhyme with which other lines. Generally, letters are used to designate rhymes, so that all lines designated with an "a" end with the same sound; similarly, all "b" lines rhyme with each other, and so forth. Some forms, including the rondeau, triolet and villanelle, have refrains or "refrain lines" (lines that are repeated in their entirety); these are generally designated with capital letters.

Meter: For our purposes, meter may be defined as "the recurring pattern of syllables and accents in the lines of a verse or poem." (Please note that this is my own definition, not that of any expert, and that it does not necessarily apply to Greek or Latin poetry, to Norse or Saxon verse, or to non-Western forms). Generally speaking, in Western, post-classical poetry, meter is a function of 1) how many syllables there are in a line, and 2) how those syllables are accented or stressed.

The basic unit of meter is the foot. A foot is a fixed pattern of syllables with stresses or accents in certain places; each type of foot has its own particular name. The one you will probably see most often in English poetry is the iamb; the iambic meter is used so commonly because it follows the natural cadence of English speech. The iamb is a unit (or foot) of two syllables, with the accent on the second. The words "belief", "distress", and "below" are all examples of iambs. (Any type of foot can also be a part of a larger word or phrase; "the house | behind | the hill", for instance, contains three iambs in a row.) The iamb's opposite number is the trochee, a foot containing two syllables with the accent on the first. The words "tiger", "fortress", and "knowledge" are all examples of trochees.

Other metric feet often encountered in English poetry are the dactyl (a unit or foot of three syllables with the accent on the first) and the anapest (a unit or foot of three syllables with the accent on the last). The words "merrily", "telephone", and "innocent" are examples of dactyls; the words "interfere" and "persevere" are examples of anapests.

Metrical descriptions of poems are based on the number and type of feet per line. A poem containing five iambic feet in each line is described as being written in "iambic pentameter", with "penta-" indicating that there are five feet or metrical units. Similarly, a poem in which each line is composed of three dactyls is described as being written in "dactylic trimeter", and so on. Specifically:
— Dimeter refers to a line of verse containing only two metrical feet.
— Trimeter refers to a line of verse containing three metrical feet.
— Tetrameter refers to a line of verse containing four metrical feet.
— Pentameter refers to a line of verse containing five metrical feet.
— Hexameter refers to a line of verse containing six metrical feet; when the meter is iambic or trochaic, a hexameter line is called an Alexandrine.
— Heptameter refers to a line of verse containing seven metrical feet.
— Octameter refers to a line of verse containing eight metrical feet.

Stanzas: Specific terms are used to describe various types of stanzas, as follows:
— A couplet is a stanza or verse containing two lines (often, but not always, rhyming with each other).
— A tercet is a stanza or verse unit containing three lines.
— A quatrain is a stanza or verse unit containing four lines.
— A quintet (or quintain) is a stanza or verse unit containing five lines.
— A sestet is a stanza or verse unit containing six lines.
— A septet is a stanza or verse unit containing seven lines.
— An octave is a stanza or verse unit containing eight lines.

Envoi: An envoi is a closing stanza (usually brief) that serves as a summary or final comment.