A Bin is a software folder into which video clips and other editing assets get organized in. You’ll have many bins per project and we’ll talk about workflow and naming these bins next week.
The term bin is a leftover from the manual editing days (not too long ago), where in the editing process the physical filmstrips would be hanging from a frame built on top of a bin. The top bar of the frame had small nails every half-inch or so from which the filmstrips would hang from their sprocket holes. The bin itself would catch any filmstrips that fell off the frame.