You may have seen the job title "computer operator" at some point and scratched your head and thought "What does that mean? Doesn't everybody operate a computer these days?"
This job title was created back when computers were a pretty new thing; people looked at the computer operator's duties and only had one existing occupation to compare them to: a telephone operator.
What a computer operator does is to work in a server room or data center monitoring alerts generated by various types of computer systems and computer-related systems: mainframes, Windows servers, UNIX servers, drives in tape silos, routers, network switches, telecommunications circuits, CRACs, air handlers, etc. Typically these data centers run 24 hours a day, 7 days a week, 365 days a year. When an alert comes in (usually via a piece of monitoring software like Tivoli Netcool or HP OpenView) the operator refers to a knowledgebase of procedures and solutions created by various tech leads at that particular center. If the alert is a simple one, the operator takes care of the problem (such as by clearing space on a drive or stopping and restarting a service or process), logs his or her actions in an incident ticket, and goes on to the next task. Thus, some of a computer operator's duties may amount to junior system administration and some of his or her duties may overlap with the work of network operations staff. If the problem is complex, the operator opens an incident ticket, calls out to the on-duty sysadmin or other senior tech and directs him or her to address the problem. The computer operator's job then is to make sure the other staff do their jobs to fix the problem; this involves sending followup emails, connecting techs and sysadmins via conference calls and emergency bridge calls, and logging all the actions everybody involved has taken in the relevant ticket.
Other duties that a computer operator may be involved with are general help desk/tech support for a company, writing technical documentation, processing tapes and other computer media for systems backups and disaster recovery, assisting senior staff with server go-lives and system debugging, maintaining equipment such as printers, and maintaining the security of the data center by issuing passwords, badges and escorting outside contractors while they're in the center.
So, as you can see, computer operators may be called upon to do a wide variety of computing duties. Quick reaction, thoroughness, and persistence are important. But this is not a job that puts much emphasis on creative thinking; in most centers, computer operators are expected to follow the established written procedures at all times, even in instances where the operator personally knows something else would be a better solution. It's also not a job for people who are phone-shy; computer operators are expected to call out to grumpy sysadmins and engineers at all hours of the day and night.
If there's one area of knowledge/training that distinguishes a computer operator from other computer professionals, though, it is their knowledge of mainframe computers. Unlike other computer systems, it's difficult if not impossible to teach yourself mainframes; first, you won't have access to them outside a data center, and second, there's a pronounced lack of training materials available on the Web. So, most computer operators learn how to work with mainframes on the job. (Some community colleges and technical schools do offer mainframe courses).
And now you may be scratching your head again, thinking "Mainframes? Aren't those ancient? Didn't every expert in the 1990s and early 2000s tell us that those old beasts were going away and would be replaced by sexy UNIX servers and whatnot?"
Yes, the experts sure did. And yet mainframes are still with us. In fact, many, many companies rely on them for critical financial transactions. Every time you get cash at your neighborhood ATM you're interfacing with a mainframe computer. You're also doing it any time you buy anything from Amazon.
But the result of 15 years of the "mainframes are going away Real Soon Now" attitude is that most computer operators are in their mid-forties to mid-sixties because companies weren't training younger employees for the job, and technical colleges weren't promoting it as an occupation.
The average fifty-something computer operator came from a blue-collar family that didn't see much need for college. Once she graduated from high school, she joined the Army because that seemed like a better gig than working down at the local factory. She took some aptitude tests when she enlisted, and based on those the Army taught her how to work the big computers that controlled their defense systems. After she got out of the military, she got a job at a data center, and that's what she's been doing ever since.
Unlike most computer professionals, the old-school computer operator is not a geek. Computers are a job he fell into, not a passion he followed into a planned career. He probably doesn't play video games, and he doesn't know anything about anime or Doctor Who. He probably saw Star Wars when it came out in theatres but hasn't watched it since unless his grandkids wanted to. He's concerned about following the rules, takes pride in his work, and he's still got a soldier's sense of duty; he doesn't complain when he's asked to work an overnight shift on Christmas. He thinks of himself as a "big box guy" and may not be terribly comfortable tinkering with his PC. He'd rather live in his home town and commute an hour than live in the city. If you want to make small talk, ask him about the local football team, or his dog, or how his kid stationed in Iraq is doing.