(deyim) 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. Inside a chassis, as in "Under the hood, this baby has a 40MHz 68030!"
By reference to looking under the hood of a motor vehicle to inspect its engine, transmission
a metaphorical area that contains the underlying implementation of something - e.g. a piece of hardware, a piece of software, an idea
Now let's look under the hood to see how the software goes about transmitting data so quickly.