A comm link was a type of communication signal that allowed two computer systems to link remotely.
In 2153, Ensign Hoshi Sato used a comm link to download a Xindi database from a hostile Osaarian merchant ship. In doing so, distance proved a critical factor. The comm link was not stable over a distance of more than about a kilometer. Enterprise had to put itself at such close range to avail itself of the comm link that it sustained heavy damage. (ENT: "Anomaly")