It's a few different factors for me. A collection consists of items you are passionate about or bring joy, while hoarding consists of things you have no emotional attachment to. Getting way too carried away with collecting to the point that it negatively impacts your quality of life also veers into hoarding territory.
Another thing, for me at least, is how presentable or "respected" the items in question are. Passionate collectors tend to take care of (or should imo) their stuff, keeping it clean and presentable, whereas a hoarder tends to just let them pile up and collect dust.
Another thing, for me at least, is how presentable or "respected" the items in question are. Passionate collectors tend to take care of (or should imo) their stuff, keeping it clean and presentable, whereas a hoarder tends to just let them pile up and collect dust.