Ultimate Guide to XSS (Cross Site Scripting)

Today i'm going to Posted a Hand Guide to XSS for Newbies . 
A lot of People ask me to write Some Tutorials on XSS , so i've Decided to also cover XSS for them . 

What is XSS ?

This in known to Everyone that XSS is also Stands for Cross Site Scripting.XSS is one of The Most Web Application Common Vulnerabilities increasingly Popular in this Time which allow a Attacker to Submitting his malicious Queries or Codes in the Target Website's "Search Boxes" as well as in the Target URL.