A system administrator, or sys admin, is responsible for setting up and maintaining an organization's computer systems, which often includes networks, servers, and security systems. They ensure that these systems are running efficiently and securely, regularly performing tasks like installing and upgrading software, creating and managing user accounts, monitoring system performance, implementing backups, and troubleshooting technical issues. In addition, sys admins often play a key role in implementing IT policies and procedures and may be involved in IT project planning and execution. They serve as the first line of defense in addressing system or network-related problems.