The Holographic Map is a device used by Star-Lord to locate the ruins of Morag. It was capable of scanning and creating holographic reconstructions of how a scanned area was like in the past.
The Broker gave Star-Lord the Holographic Map to scan and recreate the surface of the now abandoned planet Morag, showing the structures and life-forms that once populated the planet.
However, his main purpose was to locate the extremely valuable item known as the Orb, with the Holographic Map revealing its location inside a building. As soon as Star-Lord reached the building, he turned off the Map Device.