A tap is an accessory that allows for additional inside antennas.
Like a splitter it allows for splitting one cable run into multiple cable runs and antennas.
Unlike a splitter, a tap allows for asymmetrical signal strength cable runs. This means instead of splitting the signal strength equally, one output will perform better than the other(s).
This is useful for instances when giving preference to priority areas in need of coverage or longer cable runs to offset signal degradation.
It's important to remember that a tap or splitter is highly dependent on the quality of the boosted signal.
Learn more: www.wilsonamplifiers.com/splitters-taps/