Hey Mary,
Airtable saves your data on a regular basis. You can restore it if if needed. Here's a tutorial - A 7-Step Guide to Restoring Deleted Airtable Data
However, if you want to ensure you have your own backup version of your data outside of Airtable, look at On2Air Backups. It automatically backs up your Airtable data into Google Drive, Dropbox, or Box.
Hi Mary, this is a great question and something many Airtable users have asked about.
In addition to the solution listed by Hannah, I recommend checking our Pro Backup for Airtable. It allows you to back up your bases, including all records, field configurations, files & comments and restore each of these data types back to your Airtable account. Unfortunately this app does not back up your interfaces yet, but we will add this option as soon as the public API of Airtable has been updated.