Tetraquark properties will be examined in the limit of large
N_c of color in QCD. The qualitative differences between molecular
and compact teraquarks will be outlined. Consequences of
the possible existence of compact tetraquarks will be analyzed and
shown to lead to upper bounds in the N_c-behavior of their decay
widths. Open questions on theoretical grounds, related to the
dynamics of systems composed of two quarks and two antiquarks,
will be addressed.