If you want to access one computer from any computer around the world which is in the internet, you can do it with remote desktop connection
Here is a video how to connect using remote desktop connection
Firstly you have to change some settings in the computer u want to access.
Download and Install this software. An Icon will appear on your desktop.
Now just click it and your monitor turns off.
With a click on keyboard or move by your mouse, your screen again turns on.
Download this software here