In the past decade, there have been a number of exciting developments in the geometry and topology of 3-manifolds. Perelman´s resolution of the Poincare conjecture and the solution of Thurston´s Ending Lamination Conjecture by Brock-Canary-Minsky both shed new light on how their geometry is constrained by their topology. However, the problem of controlling geometric invariants (volume, injectivity radius, etc.) of a closed hyperbolic 3-manifold with topological information is still very open. We will survey some results in this direction and illustrate in more depth some geometric reflections of the `rank´ of a hyperbolic 3-manifold, the minimal number of elements needed to generate its fundamental group.