On July 30, Microsoft officials took the wraps off the first update to the Windows Phone 8.1 operating system.
A developer preview of Windows Phone 8.1 Update -- as Microsoft execs curiously have christened what is expected to be the first of several updates to its phone OS -- will be available some time during the week of August 4. The odd naming convention isn't a first; the Microsoft Operating Systems Group also decided to call the first update to Windows 8.1 "Windows 8.1 Update," despite the fact there will be a second update to that operating system, most likely on August 12.
(In the spirit of attempting to reduce confusion, I'm just going to call this Windows Phone 8.1 release "Update 1.")
Read more at: Windows Phone 8.1 Update 1 preview due week of August 4 | ZDNet
See also: Windows Phone 8.1 Update brings Cortana to new markets + new features