This document discusses the evolution of knowledge management (KM) from traditional techno-centric KM to a more social form of KM enabled by Web 2.0 technologies. Early KM focused on technology and databases but shifted to a more people-centric approach using tools like communities of practice. Now, social tools like blogs, wikis and social networks allow a new form of "KM 2.0" where knowledge sharing is decentralized and embedded in everyday work and conversations. This social KM embraces both tacit and explicit knowledge in a bottom-up and distributed way compared to the top-down centralized approach of traditional KM.