A power passing splitter, more commonly called a power pass splitter, is a device to take the signal or power from a cable at one end and feed it into two or more output connections at the opposite end.
Telecommunications Power Pass Splitters
This type of splitter is most often used to divide audio or telecommunications signal output to multiple devices within the same home or business. Televisions make the most use of these devices, allowing different users to access different channels without an independent cable line for each set.
Electrical Power Pass Splitters
These splitters work in the same way as cable splitters, but they distribute electricity rather than signals. A certain amount of loss of electricity takes place, with the loss level increasing as the number of exit ports rise. These devices can also work in reverse, as a power combiner. Power combiners take in power at two or more ports and bring it together before it exits from a single port.
Most power splitters take the rough form of the letter "T." The single port is at the narrow end of the figure, the multiple ports are at the wider end. Some splitters are shaped more like blocks, with feeds for input and output coming through the back of the block and moving out the front.