I was asked question by Jr. DBA that “What is AWE?”. For those who do know what is AWE or where is it located, it can be found at SQL Server Level properties. AWE is properly explained in BOL so we will just have our simple explanation.
Address Windowing Extensions API is commonly known as AWE. AWE is used by SQL Server when it has to support very large amounts of physical memory. AWE feature is only available in SQL Server Enterprise, Standard, and Developer editions with of SQL Server 32 bit version.
Microsoft Windows 2000/2003 server supports maximum of 64GB memory. If we have installed SQL Server 32 bit version which can support maximum of 3 GB memory on Windows 2000/2003, we can enable AWE feature to use available physical memory of server to improve performance of SQL Server. In simple words, AWE provides memory management functions which lets windows to allow more than 3GB memory to standard 32 bit application.
There are many other modification needs to be done before AWE option can be used. Please refer SQL Server BOL Using AWE for additional details.
Reference : Pinal Dave (http://blog.sqlauthority.com)