Teleoperation
means "doing work at a distance", although by "work" we mean almost anything. What we mean by "distance" is also vague: it can refer to a physical distance, where the operator is separated from the robot by a large distance, but it can also refer to a change in scale, where for a example a surgeon may use micro-manipulator technology to conduct surgery on a microscopic level.
Telerobotics
means "robotics at a distance". Many people, including us, tend to use this interchangeably with "teleoperation", which is probably a bit sloppy of us.
means "feeling like you are somewhere else". Some people have a very technical interpretation of this, where they insist that you must have head-mounted displays in order to have telepresence. Other people have a task-specific meaning, where "presence" requires feeling that you are emotionally and socially connected with the remote world. It's all a little vague at this time.