A **development container** is a running [Docker](https://www.docker.com) container with a well-defined tool/runtime stack and its prerequisites. You can try out development containers with GitHub Codespaces or **[VS Code Remote - Containers](https://aka.ms/vscode-remote/containers)**.
[GitHub Codespaces](https://github.com/features/codespaces) allows you to quickly create customized, cloud-based development environments accessible [from VS Code](https://aka.ms/vso-dl) or the web.
> **Note:** While GitHub Codespaces is in limited public beta, please _[request access](https://github.com/features/codespaces/signup) if you have not already._
The [VS Code Remote - Containers](https://aka.ms/vscode-remote/download/containers) extension allows you to clone a repository or open any folder mounted into (or already inside) a dev container and take advantage of VS Code's full development feature set.
This is a sample project that lets you try out either option in a few easy steps. We have a variety of other [vscode-remote-try-*](https://github.com/search?q=org%3Amicrosoft+vscode-remote-try-&type=Repositories) sample projects, too.
1. Select `+ New codespace` at the bottom on the pane. This will create a fork of this repository under your account and your codespace will open in a new tab.
1. If this is your first time using a development container, please ensure your system meets the pre-reqs (i.e. have Docker installed) in the [getting started steps](https://aka.ms/vscode-remote/containers/getting-started).
> **Note:** Under the hood, this will use the **Remote-Containers: Clone Repository in Container Volume...** command to clone the source code in a Docker volume instead of the local filesystem. [Volumes](https://docs.docker.com/storage/volumes/) are the preferred mechanism for persisting container data.
> **Note:** This container runs as a non-root user with sudo access by default. Comment out `"remoteUser": "node"` in `.devcontainer/devcontainer.json` if you'd prefer to run as root.
- Try adding some code and check out the language features.
- Notice that `eslint` and the `vscode-eslint` extension are already installed in the container since the `.devcontainer/devcontainer.json` lists `"dbaeumer.vscode-eslint"` as an extension to install automatically when the container is created.
You may want to make changes to your container, such as installing a different version of a software or forwarding a new port. You'll rebuild your container for your changes to take effect.
> **Note:** Remote-Containers and Codespaces also take care of dynamic port forwarding, but there may be instances in which we want to statically declare a forwarded port.
