COMPUTER SECURITY

If you have to learn what is hacking, you must be know about the basic .
like admin panels,shells,vulnerability ,...............
What is Shell ? 

programmer use this thing
admin panel is just for managing text and images on the website
admin panel can be used by a person who dont know programming language
Shell provide facility to manage the website directory too
From admin panel we can upload images
so we upload the shell in place of image and open it
and we are in if everything goes right

{this post is for many people who new in hacking & learning hacking ;) }