Definition
Cost of goods sold (COGS)
Cost of goods sold is what you paid for the items you sold in a period, excluding the cost of stock still on the shelf.
It is the cost side of gross profit: revenue minus COGS. Buying a lot of stock does not raise COGS until that stock sells, which is why a shop can be short on cash while its profit looks fine.
In Inventory Now
Unit cost is recorded on every item when you buy it, so COGS falls out of every sale automatically.
Orders and profit