[hot-rodDER talk] 1. The unDERlying implementation of a product (hardware, software, or idea). Implies that the implementation is not intuitively obvious from the appearance, but the speaker is about to enable the listener to grok it. "Let' s now look unDER the hood to see how ...." 2. Can also imply that the implementation is much simpler than the appearance would indicate: "UnDER the hood, we are just fork/execing the shell." 3. Inside a chassis, as in "UnDER the hood, this baby has a 40MHz 68030!" [Jargon File]