Inventory
Also said as Backpack, Grid inventory, Carry weight, Item slots
The screen and the rules for what you're carrying. The rule is usually one of three: a set number of slots, a weight limit, or a grid in which each item has a shape.
The rule decides what question the player asks each time they find something. Slots ask if it's worth a slot, weight asks if it's worth its weight, and a grid asks how it'll fit. Without a limit, there is nothing to decide.
Say it
“Use a 6 by 4 grid. Weapons take long thin shapes and potions take one square, with a tidy button so that fitting things stays a pleasure, and never a chore.”
Where you’ve seen it
The first Resident Evil gives Jill eight slots and Chris six, and a key takes one just as a shotgun does. Resident Evil 4 turned this into a grid, its attache case, where you rotate and fit each item. Skyrim gives you a weight limit.
Not to be confused with equipment
Inventory is everything you carry. Equipment is what you are wearing or wielding right now.