  In this overview article we present a formalism suitable for constructing
models of QFT's on curved spacetimes. The leading principle is the emphasis on
local properties. It turns out that this requires a reformulation of the
standard QFT framework which also yields a new perspective for the theories on
Minkowski space. The aim of the present work is to provide an introduction into
the framework, which should be accessible for both mathematical physicists and
mathematicians.
