  Galaxies represent the visible fabric of the Universe and there has been
considerable progress recently in both observational and theoretical studies.
The underlying goal is to understand the present-day diversity of galaxy forms,
masses and luminosities. Popular models predict the bulk of the population
assembled recently, in apparent agreement with optical observations. However,
numerous uncertainties remain, including the role that dust might play in
obscuring star-forming systems. Astronomers now seek more detailed tests to
verify that the Hubble sequence of types arises from transformations driven by
the dynamical assembly of smaller systems. Multi-wavelength surveys and studies
of the resolved internal properties of distant galaxies promise answers to
these fundamental questions.
