  We develop a unified algebraic model which satisfactorily describes the
internal structure of pion and kaon as well as heavy quarkonia ($\eta_c$ and
$\eta_b$). For each of these mesons, we compute their generalized parton
distributions (GPDs), built through the overlap representation of their
light-front wave function, tightly constrained by the modern and precise
knowledge of their quark distribution amplitudes. From this three-dimensional
knowledge of mesons, we deduce parton distribution functions (PDFs) as well as
electromagnetic form factors and construct the impact parameter space GPDs. The
PDFs for mesons formed with light quarks are then evolved from the hadronic
scale of around 0.3 GeV to 5.2 GeV, probed in experiments. We make explicit
comparisons with experimental results available and with earlier theoretical
predictions.
