If you operate a business or organization, you work to keep it running properly. If a business or organization operates, it carries out its work.

The way that something operates is the way that it works or has a particular effect.

When you operate a machine or device, or when it operates, you make it work.

When surgeons operate on a patient in a hospital, they cut open a patient's body in order to remove, replace, or repair a diseased or damaged part.

If military forces are operating in a particular region, they are in that place in order to carry out their orders.