What is the fact of using " Prerender " command / instruction by Google ? 

    Before discussing the " prerender " command, we must discuss that concept of " a cookie " .

   An HTTP cookie (also called web cookie, Internet cookie, browser cookie or simply cookie), is a small piece of data sent from a website and stored in a user's web browser while the user is browsing that website. Every time the user loads the website, the browser sends the cookie back to the server to notify the website of the user's previous activity. Cookies were designed to be a reliable mechanism for websites to remember stateful information (such as items in a shopping cart) or to record the user's browsing activity.

    So, how often prerender command has related to the cookie ?

    In Internet Browsing, the word " render " means the process of reading (HTML page ) contents and viewing it on the browser's page, but the word " Prerender " means the more earlier process of reading (HTML page) contents.

     The Prerender command is used by google when the user is expected to choose the next result of the available links in google's search page, that usually happen when the user is looking for such a company's website.

    Usually, when the browser visits a web page, it uses the cookie in order to store the page's shared information, and then it become fastely viewed by the user.

    Google insert Prerender instruction into code which indicates to the link of the first result which is choosen by the user in google search engine page, at which the browser visits that page secretly or in a hidden way before clicked,  then capture, store, and bring its information to the user when required underneath of that first link, in a more fast manner than usual.

    Such step, is considered as one of the main advantages in an instructed website done by a web developer.