Threading is a well-known feature to push time consuming tasks to a separate thread. Silverlight, by default, is running our code in the UI thread, which means that if we have a method that takes time to finish, the UI thread will be blocked and won't allow interaction until the method finishes running. By pushing this time consuming method to a different thread, the method will still take time to complete, but the UI thread won't be blocked, and the user can keep interacting with it while the method computes.

While Silverlight doesn't offer all of the threading options that the full .NET framework offers, it's still powerful enough to drive multithreaded applications. One important aspect you have to remember when working with threads is that your code runs in a whole other environment than your UI, and as such you cannot access any of the elements in the UI thread. Don't fear though; a workaround for this will be shown shortly.