Inductive bias refers to your suspicion that if the sun has risen for the last billion days in a row, then it may rise tomorrow as well. Since it is logically possible that the laws of physics will arbitrarily cease to work and that the sun will not rise tomorrow, coming to this conclusion requires an inductively biased prior.
J. Lafferty, A. McCallum, und F. Pereira. Proceedings of the Eighteenth International Conference on Machine Learning, Seite 282--289. San Francisco, CA, USA, Morgan Kaufmann Publishers Inc., (2001)