Basically they revisited a former excavation site and found new evidence, tools and human fossils, that suggests Homo Sapiens arrived a fair bit earlier in the region than previously assumed, extending the time Homo Sapiens and Neanderthals lived there simultaneously. They also found tools that were previously, due to their age, attributed to the Neanderthals and could now be identified as part of the Homo Sapiens toolkit. All in all it rewrites part of our species history during that time, especially its migration into europe.