  Dwarf galaxies that come too close to larger galaxies suffer tidal
disruption; the differential gravitational force between one side of the galaxy
and the other serves to rip the stars from the dwarf galaxy so that they
instead orbit the larger galaxy. This process produces "tidal streams" of
stars, which can be found in the stellar halo of the Milky Way, as well as in
halos of other galaxies. This chapter provides a general introduction to tidal
streams, including the mechanism through which the streams are created, the
history of how they were discovered, and the observational techniques by which
they can be detected. In addition, their use in unraveling galaxy formation
history and the distribution of dark matter in galaxies is discussed, as is the
interaction between these dwarf galaxy satellites and the disk of the larger
galaxy.
