Something about VPN Free Internet!

[finaleshot2016]

Gonna ask something about VPN Free internet, Does anyone knows how to have access into free Internet?
Well, there are many people who sells subscription into VPN and will get you an unlimited access to the internet.

How do they get that?
Any process you can share about VPN?
I'm literally curious about it and want to study about VPN. Thank you for your answers!