First, Microsoft changed the name from Internet Sharing to Mobile Hotspot, this I think is a better, universally used name of describing the feature than internet sharing.
And secondly, you can now share your data over Bluetooth. That's right, you can connect/pair any Bluetooth-enabled device to your phone to connect it to the internet.
Mobile Hotspot has always been used over WiFi connection, this is where devices can connect to your phone over WiFi and use your data to browse.
With the new Bluetooth option, devices can pair to your Windows 10 Mobile device and browse the internet, there are a couple of benefits to this. First, I'm sure this will save more battery life than if you were using your WiFi. Secondly, maybe you can still stay connected to your WiFi to do other things on your device while sharing your internet over Bluetooth, currently you cannot use your WiFi to connect to a WiFi router if you have internet sharing on.
But wait, it doesn't end there, another feature that Microsoft added is that you can remotely enable/turn on Mobile Hotspot from another device, as long as that device and your Windows Phone have Bluetooth on and are paired.
This implementation of this new feature is huge depending on how you look at it, I mean there are devices that don't have WiFi but have bluetooth, these devices thanks to Windows 10 Mobile will be able to connect to the internet.
Is this a welcome feature? Or do you think no one will use it?
Sound off in the comments below