The “vocabulary” is simply the name of the fields or the columns, or as sometimes called the “header row” in a spreadsheet used as a database. The “domain” is the industry or organizational focus - construction, wood working, transportation. The Domain Vocabulary may be as simplistic or as complex as you the Business Owner, the Customer, the Standards Organization, the Theoretical Physicist decide to make it. Lets illustrate with one example: “flush mating surfaces”.
On a mechanical drawing this is usually noted within the GD&T with plus or minus a number - 0.01 inches. However, you may say that flush is when a 0.01 inches filler gauge cannot travel farther, deeper than x percent of the full width of the mating surface. One is much more specific than the other.
For a real-life example, a head block is “flush” with the engine block when you are able to send the 0.01 inches filler gauge around the full circumference, but you cannot send the 0.02 inches filler gauge around more than 50 percent of the full circumference. However, there is more… it is also explained that a large gap creates a failure by a blown gasket - and a smaller gap increases material fatigue and thus decreases service life. To maintain this gap you need to use Part Number A gasket, and you need to set your wrench to apply no more that x.y lb/inch while bolting down.
So in this particular case the “flush mating surfaces” has not only a value, but also an explanation for the value, some instruction to reach that value, the resulting failure when the value is not maintained, and so on. This creates a more complete and accurate domain vocabulary.
One of the main purposes of FourOh-LLC is to help manufacturers and warehouses to transfer their tribal knowledge into an enterprise-level database. We call it “tribal knowledge” only because we do not have a better word / phrase to describe what is not a complete and accurate domain vocabulary. For the same reason, until we have a better description, we call a complete and accurate domain vocabulary the corporate culture.