Okay kiddo, do you know what a rhyme is? That's when words sound the same at the end. Like "cat" and "bat" rhyme because they end with the "at" sound.
A perfect rhyme is when two words not only sound the same at the end, but they also have the same vowel and consonant sounds before it. For example, "cat" and "hat" are a perfect rhyme because they both end with the "at" sound and have the same "c" and "h" sounds before it.
Sometimes, perfect rhymes can be a lot of fun to sing or say in a poem. It can make the words sound really nice together and help make a story or song even more enjoyable to hear.