The premise behind cable splitters is simple: a coaxial cable is attached to one part of the splitter, and then more cables can feed off that cable while going to different sources, namely to multiple TVs. The most common use occurs when the main coaxial line is attached to the end of the splitter, and then several lines connect to the splitter to pick up the cable service at multiple locations. If you need to install a splitter, don't fear; it's an easy process.
Check the splitter to see if the ends offer "In" or "Out" Labels. As the names would suggest, these refer to "Input" and "Output." In most cases, cable splitters will allow for "In/Out" on all connecting ends, since the splitters are typically "Passive," meaning they simply pass on information without the need for a power source.
Plug your main cable source into an "In" or "In/Out" port. You simply screw in the coaxial cable as you would do on the back of your television.
Plug the new sources to which you would like your cable to travel into the "Out" ports. For this, you simply screw in the cable that is traveling to your TV set to the open ports, and then connect the cables to your televisions.