It appears that one of the advantages of SSD over traditional HDD is that the latter has a mandatory requirement of persisting data from memory into HDD where the former doesn't need that step at all.

For instance, on my Windows 7 computer, if I shut down the computer without saving my data in my open applications, that data will be lost. By contrast, on my Android phone, I just need to simply turn off the phone without having to save my data in my open apps, and that data will remain intact in my phone.