A navigational computer or flight control computer was a computer system aboard Federation and Cardassian starships and space stations that records and displays information on the ships current location.
After being sent back in time to 2268 by Arne Darvin's use of the Orb of Time, the navigational computers of the USS Defiant noted that the ship was over two hundred light years from its original location. (DS9: "Trials and Tribble-ations")
The Dominion has the technology to stop navigational computers from recording any data. In late 2372, Amat'igan used such a device to stop the USS Defiant's navigational computers from retaining any record of the starship's journey to the Founders' new homeworld. (DS9: "Broken Link")
The navigational computer of the Chaffee was damaged in 2374, when the shuttlecraft entered the energy barrier of a planet in the Rutharian sector to rescue Captain Lisa Cusak. (DS9: "The Sound of Her Voice")