  This contribution is a review of the deep and powerful connection between the
large scale properties of critical systems and their description in terms of a
field theory. Although largely applicable to many other models, the details of
this connection are illustrated in the class of two-dimensional Abelian
sandpile models. Bulk and boundary height variables, spanning tree related
observables, boundary conditions and dissipation are all discussed in this
context and found to have a proper match in the field theoretic description.
