That's slang for connecting a computer to a cell phone and using the phone's connection. But it also means that you have connected your digital camera to your computer and you are saving and examining your photos immediately after tripping the shutter.
I used to think that shooting tethered was reserved for pro photographers. No longer. I just took a whole lot of shots adjusting the light, adjusting my exposure and adjusting my filters. I don't know what settings I'm going to like best. Once I figure it out, I'll be able to replicate it, but I just took about 90-95 shots of a 10 page book, with covers, that I recently finished. It is entirely possible that I wasted a good deal of my time taking pictures with the wrong set-up entirely.
Gaahhh! I don't like the light for any of the shots. I'll just have to wait for a different time of day and start entirely over. Oh well.