  The present contribution does not aim at replacing the huge and often
excellent literature on DFT for atomic nuclei, but tries to provide an updated
introduction to this topic. The goal would be, ideally, to help a fresh M.Sc.
or Ph.D. student (or a researcher from other fields) to become acquainted with
some basic concepts, and then move to the specialized textbooks or papers with
some ability for orienteering. We first introduce the basics of DFT, and show
the difference with the "naive" mean-field theory, that is doomed to fail as a
model even in the simple case of uniform nuclear matter. We introduce the
Energy Density Functionals (EDFs) that are used in nuclear structure, with few
examples of their applications. The concepts of symmetry breaking and
restoration are briefly discussed. We also include an introduction to the
time-dependent extension of DFT that, so far, has been implemented essentially
only in the adiabatic approximation and has been applied mainly to the study of
nuclear vibrations. With this material, we hope that any reader is able to deal
with the texts that go deeper into each of the topics, having understood that
DFT is probably the best compromise in nuclear structure theory between
simplicity, accuracy, and broad range of applicability.
