To understand poetry you must first understand the way a poem is written. This includes a variety of concepts varying from the types of sounds, to the method of lines, to the phrases, and to the specific words. One concept that can help to determine the meaning of a poem is alliteration. The alliteration can help determine where the author is making a point to emphasize important phrases. The Norton Introduction to Literature (2011) defines alliteration as "the repetition of usually initial consonant sounds through a sequence of words" (p. A1). This means that the author uses words with similar beginning sounds close together. An example of this would be big, black, bear, because the b sound is repeated.
Source: Source: Booth, A., & Mays, K. J. (2011). Glossary. In The Norton Introduction to Literature (10th Edition ed., p. A1). New York: W. W. Norton & Company. (Original work published 2006)
A tongue twister is a poem or song that is difficult to say because of the constant repeating sounds. These tongue twisters are perfect examples of alliteration. The beginning sound that is repeated is alliteration.
Source: Caitlin Ohlrogge (Alliteration from Sharon Olds) Sophia Tutorial
Watch this tongue twister video :)