That's like asking, "what's the difference between the f22 and its sales brochure?" Not trying to be mean, but I don't understand the comparison. They are wholly different in nature.

Engineering takes a desired outcome in the physical or virtual world and, using principals of math(computer science), physics and chemistry, reduced to reliable functional mechanisms aggregated in a logical fashion, constructs a device that produces on demand the desired outcome.

Marketing, on the other hand, takes a desired outcome in sales and, using the powers of persuasion, produces the desired outcome of greater sales ( I suppose).

so,

  engineering ===> math, physics, chemistry.

    marketing ===> persuasion.

In most organizations the difference is clear: marketing provides a clear benefit to the business in the form of brand recognition, sales, and stickiness while engineering is a cost not unlike the costs a retailer incurs sourcing products: sometimes it delivers substandard products and sometimes spectacular ones.

There is a relationship between the two, but they're different disciplines with different goals and different methods to achieve them.