  We provide an introduction to the experimental physics of quantum gases. At
the low densities of ultracold quantum gases, confinement can be understood
from single-particle physics, and interactions can be understood from two-body
physics. The structure of atoms provides resonances both in the optical domain
and in the radio-frequency domain. Atomic structure data is given for the 27
atomic isotopes that had been brought to quantum degeneracy at the time this
chapter was written. We discuss the motivations behind choosing among these
species. We review how static and oscillatory fields are treated
mathematically. An electric dipole moment can be induced in a neutral atom, and
is the basis for optical manipulation as well as short-range interactions. Many
atoms have permanent magnetic dipole moments, which can be used for trapping or
long-range interactions. The Toronto $^{40}$K/$^{87}$Rb lattice experiment
provides an illustration of how these tools are combined to create an
ultracold, quantum-degenerate gas.
