  We study one-dimensional disordered fermions that either undergo
metal-insulator transitions or topological phase transitions to become trivial
Anderson insulators. We focus on using entanglement to elucidate how the
spatial, momentum, and internal degrees of freedom of fermions are affected by
the presence of disorder in such cases. We develop entanglement tools that
reveal the existence of metallic states in the presence of disorder and further
show clear signatures of the corresponding localization transition even in the
presence of interactions. In systems where the internal degrees of freedom are
coupled with the motion of the electrons, topological phases develop. We
subject a topological insulator model to different types of disorder and
discuss how the topological aspects of the system can be captured through
entanglement, even at strong disorder.
