Kies is a tool that lets you manage Samsung phones from your computer, using an interface that is similar to that of other management programs like iTunes.
You can synch your phone using the cord, which is the most common, or via WiFi, which is the most comfortable way of managing your phone's content.
Aside from being able to synch your phone, the program also lets you manage all of your music, images and videos easily (both on your phone and on your computer). So you can use Kies as an authentic multimedia center to listen to your favorite songs or watch movies.
In addition to all of this, within Kies you will find access to SamsungApps, a virtual store similar to the AppStore, where you can buy and download new applications for your cellphone.
Kies is a very interesting application for Samsung smartphone users, who will find it to be an excellent tool for managing all of the content on their cellphones.