Coalgebras, corings and their comodules

The aim of this thesis is to give the reader an introduction to corings and some fundamental examples of these structures. To this end we begin with a brief overview of coalgebras over a commutative ring, then generalize this concept to the notion of corings. Finally, some main results from Sweedler's paper [17], including the construction of the canonical coring, and a method of obtaining a coring from an entwining structure will be presented.