Oracle Data Guard
Actually Data Guard is a disaster recovery solution that can be located at the same or different locations. It ensures high availability, data protection as well. In this structure, you can have 1 primary and up to 30 standby database servers. If you have active data guard license you can open standby database read only mode.
In case of disaster you can activate your passive database and continue to work within 5-10 minutes without job loss.
You can only use it if you have enterprise license otherwise we need use 3rd party solutions such as DBvisit solutions.