Propositional and Algebraic Proof Complexity We shall survey the most basic concepts of propositional and algebraic proof complexity: (Cook-Reckhow) Proof systems, optimal proof systems, coNP=NP iff optimal proof system exists. Then we shall turn to algebraic proofs systems, i.e. proofs manipulating polynomials instead of Boolean formulas: Hilbert's Nullstellensatz, Polynomial Calculus and Polynomial Calculus with Resolution. The most studied complexity measure for these systems is the maximal degree appearing in a proof. Finally we shall consider algebraic proof systems manipulating arithmetic formulas and circuits for which complexity is measured by arithmetic size instead of polynomial degree.