Windows 10 is a new version of the operating system that was released in July 2015. It's a free update for Windows 7, 8, and 8.1 users.
Upgrading vs Installing: One of the differences between upgrading and installing is the difference in the amount of space that is used. Upgrading involves adding more space to existing partitions on your hard drive, while installing involves moving all data from one partition to another with no additional space needed.
Installing Windows 10 can be done with an automated tool called Windows Easy Transfer which can transfer all your files and settings from an old computer to a new one.