Rhyme, rhythm and meter are the primary elements that make up the poetic structure of a poem. Rhyme is an important aspect to look at when learning poetry, because many of the earliest poems you learn follow simple rhyme schemes. Rhyme gives insight into both simple poetic construction and the form of more complex poetic structures, such as that of sonnets.
Poems that rhyme often have their structure shaped by something called a rhyme scheme. This is the pattern that the rhyming within the poem follows. This determines the way the poem will come together if the poet follows a set rhyme scheme, such as rhyming every second line, or creating rhyming couplets. Rhyme schemes are denoted with letters. Lines that are marked with the same letter of a rhyme scheme must rhyme. So, in a rhyme scheme of "A,B,A,B," the first and third lines would rhyme, as would the second and fourth.
Composition Word Choice
When writing a poem that he wants to rhyme, a poet considers the rhymes throughout the writing process. Obviously, word selection is limited when you look for sets of words that rhyme. The poet needs to find ways to use words that work well together while still communicating the central theme, story or message of his poem. Poets may also choose to use a rhyme to emphasize a certain point, even in a poem that does not otherwise rhyme.
The way a poem is read is influenced partly by any rhymes that may be in the poem. This is especially true when the meter of the poem causes the emphasis of the line to fall on the rhyming syllables. This makes a person reading the poetry aloud emphasize the rhyming words in the poem. Poems are sometimes written with this effect specifically in mind, resulting in a poem that is read in a somewhat consistent way.
Pacing and Rhythm
Rhymes in a poem also affect the pace at which the poem flows and the internal rhythm of the piece. A good example of this is in how internal rhymes are read. An internal rhyme is when a word is included part way through a line and rhymes with the final word on that line. Most rhymes involve the end words of different lines instead. Lines with internal rhymes move faster than lines that rhyme with different lines completely.