If you have a smartphone, must have realized that you can access multiple applications at the same time (not sharing the screen, but leaving several of them in the background). This is called multithreading (or multitasking), but not all operating systems offer a real support to the multithreading technology. Is the case of iOS, which freezes the status of applications in the background, causing them to actually stop from execution. But Microsoft has revealed that Windows Phone 8 will not have that same system, it will work with a real multitasking technology. One of the greatest examples of this feature is Skype, which can be used to make and receive calls without the need of closing a running application. While the connection is performed, the other software will continue running as well.
Not all applications should provide this support, but Microsoft ensures that the codes needed to activate this feature is available in the development kit for Windows Phone 8. That is, if developers want to enable support for the multitasking on his app, he can be able to do so easily.