I don't have the specific operating instructions for the SWEDA Infrared Massager. I recommend checking the product manual that came with the massager or contacting the manufacturer directly for detailed operating instructions.
operating software
The "Operating System" or OS
put the disk in, and follow instructions.
operating sytem
Standard Operating Procedures (SOPs)
Standard Operating Procedures
An operating or maintenance instruction manual.
Computer
Disk Operating System -DOS
Basically, any operating system is simply instructions written in code the computer understands.
Because - the computer needs a specific set of instructions to start -up. The instructions held in ROM initialise the hardware and instruct the computer to load the operating system (and where to find it on the hard-drive).