  Since Protostars and Planets VI (PPVI), our knowledge of the global
properties of protoplanetary and debris disks, as well as of young stars, has
dramatically improved. At the time of PPVI, mm-observations and optical to
near-infrared spectroscopic surveys were largely limited to the Taurus
star-forming region, especially of its most massive disk and stellar
population. Now, near-complete surveys of multiple star-forming regions cover
both spectroscopy of young stars and mm interferometry of their protoplanetary
disks. This provides an unprecedented statistical sample of stellar masses and
mass accretion rates, as well as disk masses and radii, for almost 1000 young
stellar objects within 300 pc from us, while also sampling different
evolutionary stages, ages, and environments. At the same time, surveys of
debris disks are revealing the bulk properties of this class of more evolved
objects. This chapter reviews the statistics of these measured global star and
disk properties and discusses their constraints on theoretical models
describing global disk evolution. Our comparisons of observations to
theoretical model predictions extends beyond the traditional viscous evolution
framework to include analytical descriptions of magnetic wind effects. Finally,
we discuss how recent observational results can provide a framework for models
of planet population synthesis and planet formation.
