And different vendors use the terms to mean different things.

"Wax" - generally always means a carnuba wax, you put this on last to protect the paint and keep it shiny. The waxes you buy at the local store will often be "cleaner waxes" which means that they also contain abrasives ("polish"). If you don't use a "cleaner wax" then before applying the wax you will want to use a "polish" (abrasive) or clay bar before applying the wax.

"Polish" - should only be used to indicate an abrasive but is also used as a term for a wax or a sealer. Then there is Meguiar's (who loves to confuse things) which sells "Pure Polish" which is actually a glaze.

"Sealer" - a synthetic polymer product that is used instead of a (carnuba) wax. Zaino sells some very good sealers but unfortunately couldn't quite break the habit of incorrectly calling it a polish.

"Glaze" - could be a very fine abrasive polish or could be a non-abrasive, oily filler. Can be used just before a carnuba wax in an attempt the maximize the gloss. A glaze should not be used if you plan to apply a sealer.

"Paint Protection" - either a wax or a sealer.

"Scratch Remover" - a polish (abrasive) sometimes combined with an (oily) glaze.