Agree with DrD's comments, but wanted to try to address the other part of your question.

Water slide = decals that are made of a very fragile material that carries the logo/picture/etc, usually mounted on a paper backing. They are called water slide because to use them you soak the decal in water to loosen it from the backing material, and then slide them into position on the frame....the adhesive is activated by the water and once they dry they are stuck. Be aware though that they are VERY fragile and you don't have a lot of time to play with them once you start sliding them on. Advantage is that they are extremely thin (did I mention fragile) and so they don't stick up much once on, and you can varnish or clear coat them to protect them. Think of the kind of decal that comes with plastic models.

Vinyl = decals that are printed on (or cut out of) a self-adhesive vinyl material - these usually come with paper "backing" on both sides (one to cover the adhesive and the other to hold the sticker components in place while you put it on the bike. These are durable, easier to apply, and usually not original. You don't need to clear coat them (but you can), and you will find that they tend to stick up a bit higher than a true decal. Think of the kind of sticker you can buy for your car/boat/motorcycle/etc.

An version of this type of sticker is what I think you were describing - the logo is printed on a clear backing material that is self-adhesive and vinyl - you remove the backing paper and stick it in place.

I'm sure there are plenty of folks here who can do a better job than I describing the differences.

Mark