  In this paper some qualitative and geometric aspects of nonsmooth vector
fields theory are discussed. In the class of nonsmooth systems, that do not
present sliding regions, a Poincar\'e-Bendixson Theorem is presented. A minimal
set in planar Filippov systems not predicted in classical Poincar\'e-Bendixson
theory and whose interior is non-empty is exhibited. The concepts of limit
sets, recurrence and minimal sets for nonsmooth systems are defined and
compared with the classical ones. Moreover some differences between them are
pointed out.
