Consider that the diameter of our Milky Way Galaxy is about 100,000 light-years across. The new 3D map of the Universe spans about 380 million light-years and includes 45,000 known galaxies.
One of the most important science question that astronomers are trying to explain is the source of the motion of the Milky Way, which moves about 600 km per second (370 miles per second). By making an all-sky map, they hope to account for all the galaxies that are there and get better insight on any structure revealed for the first time in the new map that may account for that motion.
Read more about the new 3D map at: Space.com.