This is what you get when you click on the "Inventory/Stats" file.

The only difference is this is a fighters "Inventory/Stats" page, other charecters will have different abilities, seeds, etc., all of that is explained in the Manual.

The backpack that all charecters start with is a 5.

The biggest one in the game is a 45, which can be extended 5 slots to a 50, by doing a quest.

This is where you can adjust your players attacks, spell order, and equip. armor, or weapons etc.

When you open a message, with an attachment, "Your Inventory" is where you wll recieve it.