  In these lectures I discuss Feynman graphs and the associated Feynman
integrals. Of particular interest are the classes functions, which appear in
the evaluation of Feynman integrals. The most prominent class of functions is
given by multiple polylogarithms. The algebraic properties of multiple
polylogarithms are reviewed in the second part of these lectures. The final
part of these lectures is devoted to Feynman integrals, which cannot be
expressed in terms of multiple polylogarithms. Methods from algebraic geometry
provide tools to tackle these integrals.
