Partly updated June 2023
General caution: Chrome OS is a secure OS by design, but this has at least one key consequence. If you change your Google account password, you will still be required to enter the old password the next time you access each Chrome OS device. Devices are encrypted with that password, so the OS needs to decrypt using the old password then re-encrypt using the new one. If you forget your old password you will lose access to your Chrome OS device data. As always, make sure you keep backups up to date.
If you have multiple Chrome OS accounts (Say, work and play), you can quickly sitch between them without logging out: