Cloud storage is a folder on the internet that you can access from any device. You can open / save files to this folder just like any other. Saving a file using one device will automatically sync it to your other devices (e.g. save a file using a Windows PC and then open it on an iPad).
You can also make certain files / folders available to other people (on a read-only basis or with full editing control). These will then appear in their cloud storage for easy access.
Chromebooks have built-in support for Google Drive, a cloud storage service included with your Google account.
You can access the contents of your Google Drive whenever you're using the Chromebook's Files app.
To learn more about Google Drive, visit:
https://support.google.com/drive
To open a file from Google Drive:
To save a Document to Google Drive:
To save a Wordbar to Google Drive: