What does each section of the panel actually do?

A quick reference for what each item in your server's sidebar does.

Console shows your server's live log and the Start / Restart / Stop controls.
Files is a browser-based file manager; for large transfers, use SFTP instead.
Databases creates and manages MySQL databases for your server, each with its own credentials.
Schedules runs tasks automatically on a cron-style schedule, not just restarts.
Users manages subuser access if you want to give someone else limited control of your server.
Backups creates and restores point-in-time snapshots of your server files.
Network shows your IP and port allocations, with space for notes on what each port is for.
Startup holds your server's startup command and game-specific environment variables (gamemode, map, App ID, player limit, and so on).
Settings covers renaming your server, viewing SFTP credentials, and reinstalling if you need a clean slate.

If you are new to the panel, the onboarding tour and Setup Progress widget both walk through these in context; this article is meant as something to come back to as a plain reference.