OS X Lion Server is server software designed for OS X and iOS devices running Lion.
OS X Lion Server makes it possible to perform a variety of tasks such as sharing files, scheduling meetings, synchronizing contacts, hosting your own website, publishing wikis, distributing podcasts, remotely accessing your network, and more. With OS X Lion Server, you can turn a Mac running Lion into a server for home offices, businesses, schools and more.
Among the many features of OS X Lion Server are file sharing for Mac, PC, and iPad, support for SMTP, IMAP, and POP servers, push notifications, and the possibility to synchronize contacts with Mac, iPad, and iPhone. In addition, it allows multiple users to access and update contacts, it has a powerful Profile Manager for mobile device management and its integrated with iChat Server.
There are many many other features too such as a Wiki Server, Podcasting tools and support for Time Machine backups using a shared destination. Note that some features require an Apple ID and/or Internet access.
However, despite the new functions introduced into OS X Lion Server, some users may feel that it has been "dumbed down" somewhat and lacks power in certain areas. However, this is good news for newbies who have never configured a server before.
OS X Lion Server makes managing a server for Macs and iOS devices easier than ever before.