  This article is meant as a gentle introduction to the "topological terms"
that often play a decisive role in effective theories describing topological
quantum effects in condensed matter systems. We first take up several prominent
examples, mainly from the area of quantum magnetism and
superfluids/superconductors. We then briefly discuss how these ideas are now
finding incarnations in the studies of symmetry-protected topological phases,
which are in a sense the generalization of the concept of topological
insulators to a wider range of materials, including magnets and cold atoms.
