Alliteration is a literary device where the same sound or letter begins several words in a phrase or sentence. It creates a rhythmic and musical quality, making the text more engaging and memorable. For example, in the phrase “Silly Sally swiftly shooed seven sheep,” the repetition of the 's' sound draws attention and adds a playful tone. Writers often use alliteration in poetry, tongue twisters, and even brand names to create a catchy effect. It can enhance the mood of a piece or emphasize certain ideas. For instance, “Peter Piper picked a peck of pickled peppers” showcases how alliteration can make language fun and lively.