A Claude Code session is your working context — conversation history, file state, permissions, and memory. Understanding how sessions work and how to manage them unlocks the ability to parallelize work, switch contexts without losing state, and recover from mistakes instantly. This guide covers session fundamentals, parallel work patterns, and five developer habits that compound over time. What Is a Session? A session is: Directory-scoped, not branch-scoped — tied to a folder location, not a git branch Persistent across context limits — survives /compact and /clear Shareable — /rename and /resume to switch between named sessions Isolated — each session has its own context window, permissions, memory Critical distinction: Sessions follow your directory, not your branch.