The clue is in the name "Virtual Private Network". It is a mechanism for simulating a point-to-point type network over existing network infrastructure without anyone else outside that mechanism (but using the same infrastructure) having access to it (unless you want them to). Usually implemented in soft/firmware. There is quite a lot more to it than that, and Google/Wikipedia are your friends here.
A VPN stands for Virtual Private Network. It is an encrypted, secured connection that encapsulates communications and allows you to access remote network resources that aren't on the Internet publicly.
It can block some Internet or local resources though, depending on the setup.
VPN or Virtual Private Network is a wizard’s cloak of invisibility in the online world:)
In simple words, it is a middleman between you and the sites you are surfing.
If you want to find a good VPN - I suggest you to read this article: blog.affilight.com/2018/04/04/finding-best-vpn-service-2018/
I like to use Tunnel Bear... But there are some good ones to choose from... http://www.vpnriot.com
Yes, I agree with you guys that VPN is very important for internet users because a lot of websites cannot be opened without using a best VPN. Alex Bryn’s comment is most impressive for me who said that VPN is a wonderful source for sharing own data without the threat of leaking. I use https://vpncoffee.com/is-putlocker-safe for safe browsing.