How Can I Make Use Of Remote Destop And Remote Assistance

In makeing use of Remote Destop and Remote Assistance you need to be connected to the same network. Is there any other means I can share my destop without being connected to the same network. Can I do that via the internet? if yes how. Or do you know any third party software that can do that? how can I get it and how to use it. Thanks for your help.

go to realvnc.com

read the documentation on there
there is a free version
use that works well.

you can control the pc remotely and type as well
I use it