How to root a Nexus device

I am developing an Android project by Nexus 7. However, when I wanted to see system folders I was rejected by "Permission denied" so I realized that I have to root it. First I tried some "One Key...

Finally, finish the configuration of this website..

The difficulty of building a private website is out of my imagination. I started this work from yesterday 11 am. After being frustrated by many things such as refused by bank when paid for domain nam...