  The field theory quantized on the {\it light-front} is compared with the
conventional equal-time quantized theory. The arguments based on the {\it
microcausality} principle imply that the light-front field theory may become
nonlocal with respect to the longitudinal coordinate even though the
corresponding equal-time formulation is local. This is found to be the case for
the scalar theory which is quantized by following the Dirac procedure. In spite
of the different mechanisms of the spontaneous symmetry breaking in the two
forms of dynamics they result in the same physical content. The phase
transition in {$(\phi^{4})_{2}$} theory is also discussed. The symmetric vacuum
state for vanishingly small couplings is found to turn into an unstable
symmetric one when the coupling is increased and may result in a phase
transition of the {\it second order} in contrast to the first order transition
concluded from the usual variational methods.
