Long Lining is what we refer to as traditional trolling. It amounts to having any number of rods out the stern or sides of the boat and pulling the bait at a pretty good distance behind the boat.
We have seen different terms for different types of trolling in the last few years primarily because many more types of trolling are now employed; like spider rigging. No doubt there will be other terms now that things like the Ipilot are gaining in popularity.
I can envision such terms as 'spot trolling', where you set anchor points on your Ipilot, when you hit a brushpile or get fish returns on the SONAR, and then tightlining/long lining multiple rods between these spots by rotating the anchor location on the remote.
How you do it is pretty basic; just get multiple baits in the water and troll around with them. However, it is more difficult than that. Getting the bait at a consistent depth, finding the right bait to troll with, boat speed and even finding the fish are what separate the fishermen from the catchermen.
When I am in the river I like to use Roadrunners with the crappie thunder bodies on them to troll, in the main lake I like the series 100 to 300 small cranks better although I like to try and let the fish tell me what they want. There are also things like planer boards you can use to get different bait presentations in and around different structure or cover.
If you have arrived here by accident, I suggest panic!