"Globular clusters are powerful tools to describe the structure
and formation of galaxies". Although this statement is a frequent
one in the literature, a quantitative link  supporting this old
idea is still missing. This talk explores a plausible way to reconcile
some features that, in principle, seem distinctive of the field stars
or the clusters. The approach shows that globulars can in fact be used
as tracers of chemical gradients, mass-to-luminosity  ratios and also
of the galaxy surface brightness profiles on large scales. A possible
connection between the "blue" globulars and dark matter appears as
an intriguing issue.