No, Windows 10 is not free as a standalone product. It requires a license for use.
Is it?
It is available for one year.
yup
Upgrading from version 7 to 10 is available for free for one year.
You get a full year to improve at no cost. Upgrading during this period grants you permanent access.
You must upgrade by July 29, 2016, to Windows 10 from Windows 7 or 8.
Ja
It manages resources more efficiently than 7.
Better.