Why don't I find a site on Internet that explains what items are for?

[Angelhearth]

I think you're going about things the wrong way here.

You're starting from the assumption that "chests" must exist, therefore you go looking for information about chests and assume that an item called a chest must be the inventory solution you are searching for. If you can't find any information about chests (or skinning monsters), it must be that nobody is explaining how to use them.

That's not actually how it works.

We don't have storage chests, therefore there is no reason for anyone to explain how to use them. And people aren't going to provide detailed information about what features are not in a game, or not by a particular term, because that list could be infinite. No wiki or item database is going to explain where you can get something that isn't there.

If you've bought a "stack of three chests" then you must have Splintered Chests. It's a crafting ingredient for a housing item.

Inventory is, basically, a notorious mess here. They made deeply-embedded poor decisions when setting up their database that have become a problem as the game increased. They can't expand the main inventory so keep working around it with segmented things.

Your main inventory, retainers and saddlebag are the entirety of standard item storage available to you. You also have the glamour dresser at the inn for storing gear you only want to keep for its appearance, and if you have a house or apartment then there is a furniture storeroom but it can't be used for other types of items. If you're in an FC there is a shared company chest.

(And no, if you ever see it and get excited, the "storage bench" furniture item is not actually storage. That's just flavour text.)

I get it that I don't get it, but you don't get it either. I don't know of any game, and I've played a few, that has chests that don't have storage space in them. It's just so far out there that I couldn't imagine it being possible. Same with skinning. In most games I know of there's a skinning profession, so I couldn't imagine it not being a thing in this game, although when you see how all mobs you slay are auto-looted and they disappear afterwards, that would explain why it isn't possible. Also, when it comes to skinning, I get why the cost is high for hides. It took me (with a lvl 44 Pal) a very good half an hour to collect 100 hides from lvl 20-21 mobs, even though I ran around in a circle and basically slayed 1 or 2 every 30 seconds (or less). With a miner about the same level it took me 10-15 minutes to collect 100 alumen for my leather-worker to make leather with.