An introduction to extra dimensions

Models that involve extra dimensions have introduced completely new ways of up on old problems in theoretical physics. The aim of the present notes to provide a brief introduction to the many uses that extra dimensions have over the last few years, mainly following an effective field theory point view. Most parts of the discussion are devoted to models with flat extra, covering both theoretical and phenomenological aspects. We also some of the new ideas for model building where extra dimensions may a role, including symmetry breaking by diverse new and old mechanisms. interesting applications of these ideas are discussed over the notes, models for neutrino masses and proton stability. The last part of review addresses some aspects of warped extra dimensions, and graviton.