Data archival versus backup and delete
Key Takeaway
Archiving moves old, rarely used records out of your production org, and users can still find and restore them. A backup is a copy of your org for disaster recovery, and deleting removes records for good after their time in the Recycle Bin.
Archiving, backing up, and deleting are three separate ways to handle Salesforce data, and each one solves a different problem. They differ in what happens to the records and in how you can get them back.
What counts as Salesforce storage
Salesforce storage is the space taken up by data in Salesforce objects (such as accounts, contacts, opportunities, and cases) and by files and attachments. You pay for the storage you use. Going over your storage limits increases your cost.