The Kies software helps users sync contacts to various services including Google, Outlook and Yahoo. It also helps transfer music, video and photos between your mobile and desktop. Kies even lets you buy apps for bada and Windows Mobile (<6.5) devices. In general, Kies will also notify you if there are any firmware updates for your device, but unfortunately that feature doesn't work with the Galaxy Tab 10.1 just yet, although you can still get updates over-the-air, so it's not such a big issue.
Still Kies is a nice solution for controlling the media on your device, so definitely give it a go if you've got a Samsung.
source: Samsung Hub via Android Police