Windows 10 comes with a very clever way of handling memory,
to reduce need to use paging when physical memory is not sufficient for applications.
When additional memory space is needed, memory is first compressed.
Performance and power usage is significantly better than classic method with HDD only.
This feature was developed for Windows 7 for using external USB memory,
improved for Windows 8.1 for "store apps", and in Windows 10 it applies for all apps.
Memory Compression in Windows 10 RTM | Seth Juarez | Channel 9