A TS performance chip is just like any other chip in that it is installed on the back of the PCM(Power Control Module). Chips modify or change timing, injector pulse width, the length of time an injector is open, and other variables to make more power. Most chips now offer more than one setting. Each setting may have different parameters for the functions that I just mentioned. A lower hp setting will generally produce lower egts and is well suited for towing. A high hp setting will may easily run the egts to 1300*. Like Ron said, with the chip you can hook up turn down the chip and go, or, unhook, turn it up and REALLY GO. TS is just one vendor for chips for our trucks. There are others. DP Tuner is also a sponsor here. Take a look at both if not others and if you decide on a chip, call them and tell them what you want. You will get the most hp for your money with a program burned specifically for your truck. Before any chip/tuner is used, I HIGHLY recommend getting guages. I hit 1400* on my pyro empty on a large hill. Only mods were the Tymar intake and 4" exhaust. Feel free to keep asking questions until you learn what you need to. We were all new at this one time or another.
Scott