Type of galaxy in the Hubble sequence characterized by the following physical properties:
Some recent observations have found young, blue star clusters inside a few elliptical galaxies, along with other structures that can be explained by galaxy mergers. In the new vision (still quite experimental), an elliptical galaxy is the result of a long process where one or more smaller galaxies, of any type, collide and fuse in a larger one.
This fusion process may at time carry on until recent or contemporary ages, and is not limited to giant ellipticals. For example, our own Milky Way is known to be "digesting" a couple of small galaxies right now.
See also: Elliptical Galaxies, SEDS Messier pages