Slow- and Fast-Light is the control of the velocity of light in a medium by light. As a fascinating new field in physics there is a fundamental interest on this effect on the one side, but on the other side there exist a lot of practical applications for telecommunication and information systems. Among these are optical signal processing, the radio frequency-photonics, nonlinear optics and spectroscopy in time domain. Furthermore, the Slow- and Fast-Light effect can be seen as a key technology for optical delay lines, buffers, equalizers and synchronizers in packed switched networks. To realize the effect there are different methods and material systems possible. Beside these especially the nonlinear effect of stimulated Brillouin scattering (SBS) is of special interest because it has several advantages. This article gives an overview about the fundamentals and limits of the Slow-and Fast-Light effect in general and based on the SBS in optical fibers. Some experimental results which were achieved so far are shown.