  This review aims to give an overview of the contribution of the Hubble Space
Telescope to our understanding of the detailed properties of Local Group dwarf
galaxies and their older stellar populations. The exquisite stable high spatial
resolution combined with photometric accuracy of images from the Hubble Space
Telescope have allowed us to probe further back into the history of star
formation of a large variety of different galaxy types with widely differing
star formation properties. We have learnt several important things about dwarf
galaxy evolution from these studies. Firstly we have found that no two galaxies
have identical star formation histories; some galaxies may superficially look
the same today, but they have invariably followed different paths to this
point. Now that we have managed to probe deep into the star formation history
of dwarf irregular galaxies in the Local Group it is obvious that there are a
number of similarities with the global properties of dwarf
elliptical/spheroidal type galaxies, which were previously thought to be quite
distinct. The previous strong dichotomy between these two classes has been
weakened by these new results and may stem from the differences in the
environment in which these similar mass galaxies were born into or have
inhabited for most of their lives. The more detailed is our understanding of
star formation processes and their effect on galaxy evolution in the nearby
Universe the better we will understand the results from studies of the
integrated light of galaxies in the high-redshift Universe.
