A short lesson from Yale's Introduction to Medical Software course covers revision control systems, tracing their evolution from early file-based tools to modern distributed systems like Git. The instructor explains why large, multi-developer projects need version tracking, then walks through Git's core workflow: clone, pull, add, commit, and push. The lesson also covers how GitHub supports team collaboration through branching, pull requests, and code review, and how these practices intersect with quality management systems relevant to medical software development. Aimed at students building software in regulated health contexts, the segment stays practical, focusing on commands and collaboration patterns rather than theory. It functions as a compact primer on why version control matters and how Git and GitHub structure a team's day to day coding practice.