# User Environments

User environments are built as immutable [Docker images](https://docs.docker.com/engine/docker-overview).
The Docker images bundle the dependencies, extensions, and predefined notebooks that should be available to all users.

Plasma relies on the [tljh-repo2docker](https://github.com/plasmabio/tljh-repo2docker) plugin to manage environments.
The `tljh-repo2docker` uses [jupyter-repo2docker](https://repo2docker.readthedocs.io) to build the Docker images.

Environments can be managed by admin users by clicking on `Environments` in the navigation bar:

```{image} ../images/environments/services-navbar.png
:align: center
:alt: Manage the list of environments
:width: 50%
```

```{note}
The user must be an **admin** to be able to access and manage the list of environments.
```

The page will show the list of environments currently available:

```{image} ../images/environments/environments.png
:align: center
:alt: List of built environments
:width: 100%
```

After a fresh install, this list will be empty.

## Managing User Environments

```{toctree}
:maxdepth: 3

prepare
add
remove
update
```