don't think thats what ment...........TechSupport is the closest.......
boot off LAN needs a whole environment setup to support it , a server and all. a common use might be somewhere where you would need security......say a bank or something. you would build a diskless workstation, on boot it would load OS and all into ram and run from there on shutdown all is gone. this way theres no data in workstation that can be stole on a drive. Another use of booting this way you might set it up to load a minimal OS then say a terminal services client (which is a client desktop where all is running on a remote server and all you get/send is keyboard/mouse video signals)
to build a machine to do this otherwise is silly and really a waste as parts a so cheap to put OS local, beside it works better there......
the other common use would be for RIS (remote installation service) where on first boot of a new empty computer it would look on the network and find a ris server which would then download and install a full OS and all programs setup ahead of time to be installed on clients from then forward would run local OS