* Phonemes are the smallest units of sound in a language that can distinguish one word from another. They are the building blocks of words, but they are not words themselves. For example, the word "cat" has three phonemes: /k/, /æ/, and /t/.
* Prefixes and suffixes are morphemes (meaningful units) that are added to the beginning or end of a word to change its meaning or grammatical function. They are not sounds themselves, but rather groups of phonemes. For example, the prefix "un-" changes the meaning of "happy" to "unhappy."
* Words are made up of one or more morphemes, including prefixes, suffixes, and roots. They are units of meaning and can stand alone.
Here's a simple analogy: think of phonemes as individual letters, prefixes and suffixes as syllables, and words as whole sentences.