Unprojection is an effort, initiated by Miles Reid, to develop an algebraic language for the study of birational geometry. Algebraically, unprojection constructs more complicated rings from simpler ones, while geometrically unprojection is a method to invert projections and to perform birational 'contractions' of divisors. The talks will be introductory and will focus on foundational and computational aspects of unprojection, and also to applications to algebraic geometry.