Alliteration is the repetition of consonant sounds at the beginning of words that are close together.
Tongue twisters are designed to be tricky to say quickly, and this difficulty often arises from the repetition of similar sounds, which is exactly what alliteration does.
Here are some examples:
* "She sells seashells by the seashore" (repetition of the "s" sound)
* "Peter Piper picked a peck of pickled peppers" (repetition of the "p" sound)
* "Betty Botter bought some butter, but the butter Betty Botter bought was bitter" (repetition of the "b" sound)
While alliteration is a common feature of tongue twisters, not all tongue twisters rely on it. Some might use other techniques like repetition of vowel sounds or similar-sounding syllables.