A combination of Mathematics and ElectricalEngineering that deals with the theory and practice of computation. Here you'll find:
- People working on mathematical models of how computers work in a very abstract way, to study both what computers can and can't do, and how well they can do what they do
- People studying the ways in which people create software, and what sorts of tools and methods can best tune this process
- People creating real software systems in any area imaginable
Computer_science at WikiPedia has a lot more information.