Segre varieties, i.e. embedded products of projective spaces, correspond to fundamental models for the applications of tensors to Multilinear Algebra, Statistics, Numerical Analysis, etc. When the point of view of Projective Geometry is taken, then classical and modern results on the Geometry of Segre Varieties are available for studies on spaces of tensors, and thus for their applications. We give some instance of Geometric properties of Segre Varieties, that produce effective tools for people working on the theory of tensors