  We present an overview of the Hartree-Fock-Bogoliubov (HFB) theory of
nucleonic superfluidity for finite nuclei. After introducing basic concepts
related to pairing correlations, we show how the correlated pairs are
incorporated into the HFB wave function. Thereafter, we present derivation and
structure of the HFB equations within the superfluid nuclear density functional
formalism and discuss several aspects of the theory, including the unitarity of
the Bogoliubov transformation in truncated single-particle and quasiparticle
spaces, form of the pairing functional, structure of the HFB continuum,
regularization and renormalization of pairing fields, and treatment of pairing
in systems with odd particle numbers.
