Counter: Available workspace. Critical square footage in kitchen required to prep, to cook, to plate, etc., without which no work in the kitchen can be executed in a practical fashion. Typical depth: roughly 25”.
Things to not do with a counter: storage of anything not used daily, including but not limited to: small appliances, kitchen gadgetry, televisions, microwaves, VCR/DVD players, picture frames, any type of pantry item [guess where those go…], pets, keys/glasses/wallets, kitchen décor or knick knacks [especially those which have no culinary function and are unable to be cleaned].
10 inch strip: the 10 inches of available depth once the rest has been filled with things on the above list. Counters with a 10 inch strip are not recommended for the preparation of food.
Ps. For a quick read of some people hating on what I do, check out the comments on this article.