OPOSSUMS ARE MARSUPIALS. If you open just about any field guide to North American mammals, the opossum will probably be the very first of the 380 or so mammal species described. That's because opossums are our only marsupial, and marsupials are considered very ancient forms of mammals.
operator - an agent that operates some apparatus or machine; the operator of the switchboard. manipulator. causal agency, causal agent, cause - any entity that produces an effect or is responsible for events or results. company operator - an operator who works for a company. driver - the operator of a motor vehicle.
In addition to these operators, many programs and programming languages recognize other operators that allow you to manipulate numbers and text in more sophisticated ways. For example, Boolean operators enable you to test the truth or falsity of conditions, and relational operators let you compare one value to another. (2) A computer operator is an individual who is responsible for mounting tapes and disks, making backups, and generally ensuring that a computer runs properly.