Robotic swarms represent the application target of the studies presented in this book and therefore required the reader to be acquainted with the main concepts behind this branch of robotics. The introduction of swarm robotics principles is done only after presenting multi-robot systems, in comparison with single robot systems. Among the concepts that are defined in this chapter we mention: swarm robotic system, stigmergy and neighborhoods. After this theoretical introduction, the chapter continues with a presentation of robotic platforms that can be used to validate swarm algorithms. Among the robots listed are the Kilobot, the e-puck and the Khepera. As swarm robotics generally requires a large number of individuals, the costs of running experiments on real robots can become high. For this reason, robot simulation platforms are also discussed at the end of this chapter.