Caching of the installers...
Into a folder of our choosing...
Allowing us to reuse them to update many, many PCs...
Reducing internet data usage...
Potentially saving money...
Reducing network usage...
Reducing time needed for updating...
Reducing the carbon footprint of software distribution/updating...
Why?
There already is a topic about this: https://patchmypc.com/forum/index.php/topic,8434.0.html