The Visual Studio Code Dev Containers extension lets you use a Docker container as a full-featured development environment. It allows you to open any folder or repository inside a container and take advantage of Visual Studio Code's full feature set. A devcontainer.json file in your project tells VS Code how to access (or create) a development container with a well-defined tool and runtime stack. This container can be used to run an application or to provide separate tools, libraries, or runtimes needed for working with a codebase.