The Fog Computing paradigm was introduced to extend and overcome the limitations imposed by cloud centric architectures with respect to their assumptions on connectivity, bandwidth and latency. As such Fog Computing aims at bringing elastic and high-performance computing, storage and communication at the edge. Early demonstrations of Fog Computing architectures such as those carried on the Barcelona Smart City demonstrator, have proved the effectiveness of this paradigm and initiatives such as the Open Fog Consortium aim at popularizing and accelerating the adoption of Fog computing as one of the key paradigms at the foundation of Internet of Things. In this presentation we will explain the forces that drove the introduction of Fog Computing and provide a thorough definition of the underlying architectural style. Additionally we will explore the relationships and synergies that exist between Fog and Cloud Computing. Finally we will show how PrismTech’s Vortex naturally supports Fog Computing Architectures.