The Covert Ops is an add-on for the Terran Science Facility. The other available add-on for the Science Facility is the Physics Lab and only one add-on can be attached and utilized at a time. The Covert Ops unlocks the ability to produce Ghosts from the Barracks and Nukes. It is also the research facility for the various special abilities and upgrades for the Ghost.
Because Ghosts are not commonly used in professional gaming, the Covert Ops add-on is not frequently constructed.
Upon lift off of the attached Science Facility, the Covert Ops add-on loses its effectiveness.