Cline is a VSCode extension that brings Claude into your editor as an autonomous coding agent. Unlike Cursor (which is a separate IDE), Cline runs as an extension inside VSCode—you keep your familiar editor and add Claude as an agent. You describe a task in plain English, Cline reads your codebase, runs terminal commands, edits files, searches documentation, and solves problems autonomously. Cline is more ambitious than autocomplete tools (Copilot) but more autonomous than interactive editors (Cursor, Aider). It operates in "agent mode" by default—you set a goal and Cline works toward it without stopping for approval on each edit.