[Samsung Galaxy Nexus] DamienChaos:
I totally get your understanding of those terms; but my intent with using them is more as a description of the end result of their use; independent of their application function. In all honesty, it is just a matter of semantics. So, to be a bit more precise, here's what I mean by the terms I've used previously, as applied to auto care products:

Wax - An agent which produces the desired result (e.g. shine, protection) by placing a coating on the intended surface.

Polish - An agent which produces the desired result (e.g. shine, protection) by enhancing the properties of the surface itself; only coating such surface, if at all, to a very small degree.

Sealant - A property that causes an agent to chemically bond with itself as well as the intended surface.

Abrasive - A property of an ingredient in an agent that removes a layer of the intended surface so as to permanently reduce any unevenness; like sandpaper, such ingredients can vary from very mild to extremely abrasive.

Filler - An additive in an agent that that causes certain components of an agent to get caught, and remain, in low-lying areas of the intended surface so as to temporarily reduce unevenness.

Silicon - An additive in an agent that increases the reflective and non-stick qualities of the intended surface temporarily.

Carnauba - A natural base for some agents, typically waxes, which is desirable due to its ability to coat, protect, and enhance smooth surfaces.

Synthetic - A wide-ranging term for various proprietary non-carnauba bases for some agents, typically polishes, which is typically desirable due to its ability to enhance the optical properties of an intended surface, while maintaining optical clarity and chemically bonding with the surface to create lasting protection, as well as containing various additives to enhance the desirability of the agent, such as the ability to reduce UV penetration.

Petroleum Distillates - A proprietary polymer blend which acts as the key ingredient in the synthetic base for some polish agents.

So, both waxes and polishes can, but don't have to, be abrasive, contain filler, or act as a sealant; mostly it depends on their application function. In general, because carnauba-based agents typically offer their advantages via a coating mechanism, I lazily refer to them as waxes; conversely, because synthetic or petroleum distillate based agents offer their advantages by enhancing the surface itself, I call them polishes. Visibly, if one has two black cars and uses carnauba "wax" on one and synthetic "polish" on the other, the waxed vehicle will appear much more reflective than the polished car, the latter of which will have a more 'natural' shine; however the natural reflectivity of the polished car will outlast the almost-greasy wax shine due to the fact that the carnauba coating deteriorates quicker. Of course I'm speaking in generalities here, everyone has their favorite product and YMMV!

However, under these definitions, a specific description of what I have on my phone screen (Z-2) is a petroleum distillate based polish sealant without fillers, silicon, or abrasives. It has the additional advantage of being 99+% optically clear and having built-in UV protection, so originally started applying it to my car's windshield/windows. As I only use my windshield wipers in the most torrential of rains (or if not moving), that seemed to indicate an oleophobic properties which gave me the idea to use it on my glasses, sunglasses, and, eventually, phone.

Hope that helps!

--DC