  Quantum computers take advantage of interfering quantum alternatives in order
to handle problems that might be too time consuming with algorithms based on
classical logic. Developing quantum computers requires new ways of thinking
beyond those in the familiar classical world. To help in this thinking, we give
a description of the foundational ideas that hold in all of our successful
physical models, including quantum theory. Our emphasis will be on the proper
interpretation of our theories, and not just their statements. Our tact will be
to build on the concept of information, which lies central to the operation of
not just computers, but the Universe. For application to quantum computing, the
essence of quantum theory is given, together with special precautions and
limitations.
