z/OS
z/OS is a 64-bit operating system developed by IBM for its mainframe computers, particularly the IBM Z series. It is designed for high availability, security, and scalability, supporting large-scale enterprise workloads such as transaction processing, database management, and batch processing. z/OS integrates traditional mainframe features with modern technologies like UNIX System Services and Java.
Developers should learn z/OS when working in industries like banking, insurance, or government that rely on legacy mainframe systems for critical, high-volume transactions. It is essential for maintaining and modernizing existing mainframe applications, as well as developing new ones that require robust security and reliability. Use cases include COBOL programming, CICS transaction processing, and DB2 database management on IBM Z hardware.