Modules are optional components you can use to tailor your Editor installation.
You can limit the Editor download/install size if you select only the modules that you require.
Add modules to the Unity Editor
To add modules to your version of the Unity Editor:
In the Hub, go to Installs.
Right-click on or select the gear icon to open the contextual menu.
Select Add modules to open a window that lists all of the platform Build Support, language packs, and development tools that you can install. For modules that are already installed for that version, the DOWNLOAD SIZE column displays the word Installed.
To view the memory space required to install a module, select it. The top right of the window displays the information. This indicator also displays how much space is available on the install path you have selected.
Select the modules.
Some modules require you to accept the Terms & Conditions before you can install them.