Those that have used and become comfortable with how the Share Charm works in Windows 8.x, will be happy to hear that the function is not going away in Windows 10. In fact, Microsoft is making it available in more places.
For me, the Share Charm is invaluable. I use it constantly and have become very accustomed to how it works in Windows 8.x. Sharing content, whether its pictures, good reads, or files, has become a staple for the modern crowd. So, while the Charms are taking a much different turn in Windows 10, it's good to see that some of the better Windows 8.x functionality isn't going away, just being moved around.
One of the places the Share functionality now shows up is in File Explorer. Open File Explorer, select a file (any file) and clicking the Share tab reveals the familiar Share Charm icon.
The Share Charm still works the same as before and causes the old Charm bar to pull out from the right side of the screen, allowing you to select the vehicle for sharing. I don't have a lot of apps installed on my Windows 10 test system, so the only available option for me (shown below) is the email app.
Of course, any app that provides sharing capability that is registered with the system will show up here.
Microsoft states that this functionality is in its early stages and new abilities could show up in the coming months.