  A review of the present observational and theoretical status of elliptical
galaxies is presented with the aim to clarify whether the monolithic or the
hierarchical, is a more viable scenario for the origin of these structures. We
describe the dynamical structure of elliptical galaxies using photometric and
spectroscopic data, in particular 3D observations from integral field
spectrographs, with emphasis on properties such as brightness distribution,
velocity profiles, central structures like "cuspy" profiles and "cores", as
well as central supermassive black holes.
  We also report on the main relations between these quantities like the
fundamental plane and colour-luminosity diagram. We present observational
evidences for the presence of dark matter in the elliptical galaxies and
examine the theories of galaxy formation within the framework of a cold dark
matter cosmological model. We discuss the formation of large-scale structure,
Press-Schechter theory and universal density profile of dark matter halos.
Subsequently, gas dynamics, star formation, feedback, angular momentum,
morphology and the epoch of galaxy formation are studied and comparison between
disks and spheroids are made. Valuable insights into the formation epoch of
elliptical galaxies are provided by deriving the mean metallicities and ages at
different redshifts through the study of different population synthesis models
(single-burst and evolutionary models) in particular the magnesium to iron
ratio.
