the cow hide is split into two, the top part of the hide is commonly known as leather the bottom as faux, discomfort,hot and sticky in summer and cold in winter? to be honest dont really know just the sales pitch i use for selling sofas.
similary grades of leather? If something has a grade number its more likely to relate to the storage bay its in, as there is only one grade...that from a cow. semi analine analine pigmented relate to the leather being surface painted or not.
Faux anything is a fake - can be any kind of material made to look like leather (eg - vinyl plastic). In the US they often use the term Naugahyde (which I suspect is a trade name for a particular type.
The term faux is used (French) otherwise they would have to say false, or fake, or imitation and then there would be no confusion.
Types of plastic are frequently used - it has to be very good imitation indeed to have the strength and breathability of real leather.
*Raven* - if you're telling people in a sales situation it's split leather you better check your facts very very carefully, as you may be seriously misleading them.
By and large imitations aren't breathable (hence hotter/stickier). And being mainly plastic use oil in their manufacture. There are a lot of cowhides around as a natural byproduct of raising cattle!
Personally I wouldn't use either on upholstery - if that's what you are thinking of - but then again it's very hot in the summer here, and I couldn't be doing with anything except fabric, and we usually have a washable throw on it as well.