  Much of the progress in Astronomy has been driven by instrumental
developments, from the first telescopes to fiber fed spectrographs. In this
review we describe the field of astrophotonics, a combination of photonics and
astronomical instrumentation that has the potential to drive the next
generation of developements. We begin with the science cases that have been
identified as possibly benefiting from astrophotonic devices. We then discuss
devices, methods and developments in the field along with the advantages they
provide. We conclude by describing possible future developments in the field
and their influence on astronomy.
