  Very high energy gamma-ray observations offer indirect methods for studying
the highest energy cosmic rays in our Universe. The origin of cosmic rays at
energies greater than $10^{18}$ eV remains a mystery, and many questions in
particle astrophysics exist. The VERITAS observatory in southern Arizona, USA,
carries out an extensive observation program of the gamma-ray sky at energies
above 85 GeV. Observations of Galactic and extragalactic sources in the TeV
band provide clues to the highly energetic processes occurring in these
objects, and could provide indirect evidence for the origin of cosmic rays and
the sites of particle acceleration in the Universe. VERITAS has now been
operational for ten years with the complete array of four atmospheric Cherenkov
telescopes. In this review, we present the status of VERITAS, and give few
results from three of its key scientific programs: extragalactic science,
Galactic physics, and study of fundamental physics and cosmology.
