What is a bulkhead?

I have recently switched rolls within the company that I work for (Williams Kitchen & Bath) and am learning the basics of Kitchen and Bath design. I was shadowing the sweetest woman in the world today, Lorna, and she taught me a ton of new things. She took everything very slow and even though her background is from a builders standpoint she was able to dumb things down enough for me to understand her basic design process. I learned that the standard size from the counter to the cabinets in a kitchen is 18 inches, the standard cabinet depth is 12 inches and the standard plate size is around 10 inches.

These things were all interesting to me but when she kept referring to one specific piece of certain kitchens I kept finding myself going "uh huh, yep, ok, sure..." even though I had no idea what she was talking about. Bulkheads. It was one of those things that I thought I should know so I went along with it, and it wasn't until around 1pm that I finally admitted that I had no idea what a bulkhead in a kitchen was. So NOW I know that a bulkhead is a soffit that juts out over the top of the cabinets. It is not common for people to incorporate bulkheads into the buildings anymore but originally they were used to essentially "hide" all the wiring (especially from lighting), or to house vents and pipes. Some people opt to remove them during remodel, or hide them with crown molding or some people just deal with them I suppose. I have a feeling I will be learning a LOT in the next few months about Kitchen & Bath Design!