Modules are optional components that allow you to tailor your Editor installation to suit your needs. You can limit the Editor download/install size if you select only the modules that you require.
To add modules to your Unity Editor, go to the Installs tab and right click on the Editor version or select the gear icon [image] to open the contextual menu. Select Add modules to open a window that lists all of the platform Build Support, language packs and dev tools that you can install. For modules that are already installed for that version, the DOWNLOAD SIZE column displays the word Installed.
You can view the memory space required to install modules when you select them by looking at the top right of the window. This also says how much space you have available on the install path you have selected.
Select the modules that you want to add and select Install to begin downloading them.
Note: Some modules require you to accept the Terms & Conditions before you can install them.