assert equal 'string1' "string1"
  ```

  :::

- Less commonly, the name of a module already created with the [`module`](/commands/docs/module.md) command. While it is possible to use this command to create a module at the commandline, this isn't common or useful. Instead, this form is primarily used by module authors to define a submodule. See [Creating Modules - Submodules](./creating_modules.md#submodules).

### Module Definitions

The second argument to the `use` command is an optional list of the definitions to import. Again, the module documentation should provide recommendations. For example, the [Standard Library Chapter](../standard_library.md#importing-submodules) covers the recommended imports for each submodule.

Of course, you always have the option to choose a form that works best for your use-case.

- **Import an entire module/submodule as a command with subcommands**

  In an earlier example above, we imported the `std/log` module without specifying the definitions:

  ```nu
  use std/log
  log info "Hello, std/log Module"
  ```

  Notice that this imports the `log` submodule with all of its _subcommands_ (e.g., `log info`, `log error`, etc.) into the current scope.

  Compare the above to the next version, where the command becomes `std log info`:

  ```nu
  use std
  std log info "Hello, std Module"
  ```

- **Import all of the definitions from a module**

  Alternatively, you can import the definitions themselves into the current scope. For example:

  ```nu
  use std/formats *
  ls | to jsonl
  ```

  Notice how the `to jsonl` command is placed directly in the current scope, rather than being a subcommand of `formats`.

- **Import one or more definitions from a module**

  Nushell can also selectively import a subset of the definitions of a module. For example:

  ```nu
  use std/math PI
  let circle = 2 * $PI * $radius
  ```

  Keep in mind that the definitions can be:

  - Commands
  - Aliases
  - Constants
  - Externs
  - Other modules (as submodules)
  - Environment variables (always imported)

  Less commonly, a list of imports can also be used:

  ```nu
  use std/formats [ 'from ndjson' 'to ndjson' ]
  ```

  ::: note Importing submodules
  While you can import a submodule by itself using `use <module> </submodule>` (e.g., `use std help`), the entire parent module and _all_ of its definitions (and thus submodules) will be _parsed_ when using this form. When possible, loading the submodule as a _module_ will result in faster code. For example: