To understand this control, I think you should familiarize yourself with Threading. It's a relatively nice control. You can use it when you want to perform simultaneous tasks. For example, you have an ftp directory which serves as a dump folder for zipped folders which contains xml files that you will eventually process. You're currently processing some xml files with your program and your program has a separate thread (background worker) which will check the existence of zipped folders, another thread for importing, extracting then queuing those files for your next batches of xml to process. Something like that. I hope you get my point.