Vicinity
Don't litter.
A lot of times there will be a need to interact with items outside of the inventory space. It is easiest to do it on the ground, and that is always shown in the vicinity.

Vicinity And Filters
Crafted or dropped items will appear around the player's vicinity together with any items found while looting. Chests, vehicle inventories, and any items with their own inventory appear at the bottom part of the vicinity window for easier transfer. Add items faster to your inventory by double-clicking them in the vicinity tab.
Above the vicinity window there are several icons which can be used to filter out items in the vicinity for easier item management. Clicking on each filter will show the items of the appropriate category and hide all the rest.
Official SCUM in-game content (the game’s own text, translated by the studio).