We give a basic overview of computational complexity, query complexity, and
communication complexity, with quantum information incorporated into each of
these scenarios. The aim is to provide simple but clear definitions, and to
highlight the interplay between the three scenarios and currently-known quantum
algorithms.Comment: 28 pages, LaTeX, 11 figures within the text, to appear in "Collected
Papers on Quantum Computation and Quantum Information Theory", edited by C.
Macchiavello, G.M. Palma, and A. Zeilinger (World Scientific