Source Code Management (SCM) is a system that helps developers track and manage changes to their code over time. It allows multiple people to work on the same project without overwriting each other's contributions. By keeping a history of changes, SCM makes it easier to identify when and why modifications were made, which is crucial for debugging and collaboration. Common tools used for Source Code Management include Git, Subversion, and Mercurial. These tools provide features like branching, merging, and version control, enabling teams to maintain organized and efficient workflows. Overall, SCM is essential for software development, ensuring code integrity and facilitating teamwork.