When we begin a new product we start with a spec sheet that details our expectations for the product's performance: a list of features and functions, projected costs, etc.
Think of it as a wish list.
From there we knuckle down and begin the process of actually designing all the bits and bobs that make it a real product. That's an easy year to year and a half including all the many trips to the listening room and back to the design bench.
And, at the end of that entire process, we place the unit on the measurement desk and write yet another spec sheet.
This time, the spec sheet reflects what we actually wound up with and it is this that you see when you go to a product page and look for the specs.
Hopeful specs vs. actual specs.