Activities performed by a system administrator (or
"admin", "sysadmin", "site admin") such as monitoring security
configuration, managing allocation of user names and
passwords, monitoring disk space and other resource use,
performing backups, and setting up new hardware and
software.
system administrators often also help users, though in a large
organisation this may be a separate job.
Compare
postmaster,
sysop,
system management,
systems programmer.