We've already pointed out that data archival is a means of file storage for data that is no longer active but needs to be accessible in case something happens later down the road.
A data backup is a copy of current information stored in a convenient location so that when disaster strikes (natural disaster, data corruption, etc.), they have the option to return to a previous point of data from a specific time rather than start over from scratch to rebuild their business.
A data archiving strategy will be focused on long-term archive storage. Backup data may be more readily accessible and relied on for different data protection needs.