Windows 10 removed the option of letting users decide how and when the updates are installed. Windows 10 went the route to automatically update the system when not in use, this also meant updates will be downloaded in the background while using it. It will only install it when the system is idle. People hated this for obvious reasons, background downloading took some processing power and internet speed which affected the day to day use especially for laptop users. This also affected the battery life.
Microsoft addressed this in their Anniversary Update, by adding active hours it gave some control over a few things regarding the update. But it still had the issue of big update files. In the next Windows 10 update, this issue will be settled.
Microsoft's new update delivery technology, Unified Update Platform (UUP) is to help reduce the download size of updates for PCs. This is done by only providing the differential updates to your PC, only the changes that have been made since you last updated your device.
UUP will most be useful to PC users as the download size for updates could be decreased by 35%. How this works is very simple, when an update request is sent by a device, UUP will automatically evaluate which updates are needed by a given device and download the required patches only.
UUP won't affect your experience or change the method or settings how you update your system, this is a behind-the-scenes technology to serve Windows 10 users with better system updates.
Windows 10 beta users, Windows Insiders have been getting this type of update (UUP) from the past few builds and so far Microsoft says it has updated more than 400 million Windows 10 devices week after week.
Source :Windows Blog | Introducing Unified Update Platform (UUP)