Hardware Description Language (HDL) is a type of computer language used to describe the way a computer works and how it should look. It's like giving instructions to a computer to build something. It is like a blueprint for the computer and tells it what kind of parts it needs and how they should be connected. For example, HDL might tell the computer that it needs a processor, a memory chip, and a graphics card, and then tell it how the parts should be connected to each other. It's like the computer's very own electrical engineer!