Microsoft Exchange Server 2013 contains a lot of new functions that make life a lot easier:
Exchange Administration center- Earlier Exchange Server had EMC (Exchange Management Console) and the ECP (Exchange Control Panel) that is web-based. Exchange 2013 everything moved to the web console, and thus it makes it easier to access it from anywhere.
Exchange Architecture- In Exchange 2007 and 2010 five server roles were used and now Microsoft has two server roles one is Client Access Server role and Mailbox server role.
SQL for storage- In previous versions of Exchange server, the ESE (Extensible Storage Engine) database engine was used. But in Exchange 2013, the ESE code has been rewritten in C# to be more resilient and able to handle problems.
Public folder changes – Public folders are still available in Exchange 2013 but implemented little differently. They are part of Exchange Administration Center and stored in other mailbox databases and can be relatively backed up easily with other mailbox databases.
PowerShell cmdlets- Previously Exchange Server 2013 had 13 various PowerShell cmdlets, but now it has new 187 PowerShell cmdlets added.
Anti-malware protection- Exchange server 2013 have better malware protection and stopping it from reaching internal network.
Improved integration with Lync and SharePoint- Lync Server can now archive content and use exchange server 2013 as contact store.
Mobile friendly outlook web app- User interface for Outlook web app has been redesigned to look good on tablets, desktops and other smartphones. Outlook now has a better look, no matter which device you are using.