The operations manual is intended to remind employees of how to do their job.
The manual is either a book or folder of printed documents containing the standard operating procedures, a description of the organisational hierarchy, contact details for key personnel and emergency procedures.
The difference between a operating manual and a user guide is: an Operating Manual simply tells you the specifications of your device and technical characteristics.
But a User Guide is a step-by-step way to learn how to use the device.