Asp.net MVC 5 or Asp.net core MVC

Question

Hello, 

I am trying to learn Asp.net mvc,i already started some mvc tutorial on youtube

https://www.youtube.com/watch?v=-pzwRwYlXMw&list=PL6n9fhu94yhVm6S8I2xd6nYz2ZORd7X2v 

, so i am little bit famaliar with it, but i am confused in different versions of mvc, now there is Asp.net mvc 5 as well as Asp.net core. so which version of MVC should I start to learn.