Virtual Storage Access Method (VSAM) - davidkhala/IBM GitHub Wiki

https://www.ibm.com/docs/en/zos-basic-skills?topic=set-what-is-vsam

an access method and data set organization used by IBM mainframes to manage files on disk

Secured

• encrypt-like: VSAM keeps disk records in a unique format that is not understandable by other access methods.
• VSAM files cannot be routinely displayed or edited with ISPF.

Usage:

• VSAM is used primarily for applications. It is not used for source programs, JCL, or executable modules.