You know, stuff... Things. Clutter. Everything that isn't nothing.
Often used to specifically refer to "stuff" that we want, "stuff" that we buy, "stuff" that we don't need, "stuff" that we end up just throwing away, or that our houses get filled with, or that we end up getting extra storage room just to keep it locked away somewhere so that we don't have to throw it away or admit we never needed it. THat kind of stuff.
The Story of Stuff: https://www.youtube.com/watch?v=9GorqroigqM
Although it doesn't have to be used that way. It's a pretty generic word, after all. That's how it was first used on Openbook, though.
See Also: https://storyofstuff.org/