  This article provides a formalism making it possible to manage the solutions
of the direct and inverse kinematic models of the fully parallel manipulators.
We introduce the concept of working modes to separate the solutions from the
opposite geometrical model. Then, we define, for each working mode, the aspects
of these manipulators. To separate the solutions from the direct kinematics
model, we introduce the concept of characteristic surfaces. Then, we define the
uniqueness domains, as being the greatest domains of the workspace in which
there is unicity of solutions. The principal applications of this work are the
design, the trajectory planning.
