Cloud holds everything behind the scenes for sites that store data:
Database and SQL editor: the data your site saves
Users: visitors who have accounts on your site
Storage: uploaded files
Secrets: API keys for other services, kept private
Edge functions: server code your site runs
Logs and Usage: what's happening and how much is used
Emails: sending emails from your site (Pro)
You don't need to set any of this up yourself. Ask the chat for the feature and it configures Cloud for you.