  The challenge of dark matter may be addressed in two ways; by studying the
confrontation of structure formation with observation and by direct and
indirect searches. In this review, I will focus on those aspects of dark matter
that are relevant for understanding galaxy formation, and describe the outlook
for detecting the most elusive component, non-baryonic dark matter. Galaxy
formation theory is driven by phenomenology and by numerical simulations of
dark matter clustering under gravity. Once the complications of star formation
are incorporated, the theory becomes so complex that the brute force approach
of numerical simulations needs to be supplemented by incorporation of such
astrophysical processes as feedback by supernovae and by active galactic
nuclei. I present a few semi-analytical perspectives that may shed some insight
into the nature of galaxy formation.
