This is one of our industry jargon terms that is sort of self explanatory, yet there is also no commonly agreed upon definition. In a very general sense off line means inactive, or not in use. Equipment that is off line is generally considered to be either powered down or otherwise not connected to the system that is in use. Off line editing, however, is a phrase used in post production to describe editing that occurs apart from the main editing of a project.

A power supply which receives its input power from the AC line, without using a 50/60 Hz power transformer prior to rectification and filtering, hence the term "off line" power supply.

equipment, devices, or person not in direct communication with a computer

Area designated for sub-assembly operations not performed on main body conveyer.

On a railroad carrier other than the one in consideration, but also involved in the specific movement.

Time spent preparing files to be sent electronically before connecting to the network.