A lot is a listing.
Our family has run online and public philatelic auctions for decades. Lots have run from single stamps to a dozen cartons of remainders.
Let's use stamps as an example.
I have currently up Quarterly Packs of Canada Post issues. These are not difficult to buy when they first come out, but can be a few years later.
I could put up one listing with one pack of the four I have on hand. When it sells, I could use 'Sell Similar' to relist another.
I could put up one listing for one pack noting that I have four available. In this case, when the first sells, the listing does not end, but repeats until all four are gone.
I could put up one listing with all four in the same lot.
