Phonotactics is all about the rules that tell us which sounds can go together to form words.
Just like putting together a puzzle, we have to choose the right pieces to make the shape we want.
In the same way, when we create words, we have to use the right sounds in the right order to make sense.
For example, we need to put vowels and consonants together in a specific way to create words like "cat" or "dog".
If we try to change the order of the sounds, such as saying "tac" instead of "cat", it may not make sense to other people.
Phonotactics helps us understand the rules that make it possible to create words that other people can understand.