Note: This term may have other meanings in other contexts. Here, we are defining it in the context of a distributed database.
In the context of databases, on-prem describes a database deployment in which a company’s data is stored on a machine that they own, rather than stored with a public cloud provider such as GCP or AWS. Companies often choose to store proprietary or high-security data on-prem because they can have more control over the safety of it.