  The pion charge and scalar form factors, $F_1(Q^2)$ and $F_0(Q^2)$, are first
calculated in different forms of relativistic quantum mechanics. This is done
using the solution of a mass operator that contains both confinement and
one-gluon-exchange interactions. Results of calculations, based on a one-body
current, are compared to experiment for the first one. As it could be expected,
those point-form, and instant and front-form ones in a parallel momentum
configuration fail to reproduce experiment. The other results corresponding to
a perpendicular momentum configuration (instant form in the Breit frame and
front form with $q^+=0$) do much better. The comparison of charge and scalar
form factors shows that the spin-1/2 nature of the constituents plays an
important role. Taking into account that only the last set of results
represents a reasonable basis for improving the description of the charge form
factor, this one is then discussed with regard to the asymptotic QCD-power-law
behavior $Q^{-2}$. The contribution of two-body currents in achieving the right
power law is considered while the scalar form factor, $F_0(Q^2)$, is shown to
have the right power-law behavior in any case. The low-$Q^2$ behavior of the
charge form factor and the pion-decay constant are also discussed.}
