Imagine a situation, you don't have brightness up key on your keyboard, or brightness up key is not working, than of your friend reduce the brightness to 0 level when you are seeing your laptop 😂😂

What you will do? You won't see anything on the screen, one way is to force shutdown by pressing and holding the shutdown button,but this will affect os as well as your current important work.

So do one thing, instead of doing such things, try the below idea
* Press 
 Alt + control + T
* Type 
echo 500 | sudo tee /sys/class/backlight/intel_backlight/brightness
* {{yourPassword}}
* Enter


Hurray, your screen brightness increased to 500 level
🥰