Certified Site Metrics are metrics that are directly-measured from the website instead of estimated.The website owner has installed an Alexa Certify Code on the pages of their site and chosen to show the metrics publicly.Other wise this will affects your website negatively.It's very important to use pictures on your website to bring up the main concepts of your website. Search engines understand the pictures by their alt tags.
Domain is either you or your company's ID in the Internet, when you apply to connect to Internet, they will give you protocol number. Every device connected to Internet has an IP number. Webmasters, publicists and ad networks assess your website that base on alexa rank estimation of your site or online journal.
The links on the other websites are called external link.
You should not have too much external links on your website.
Nameservers are a.root-servers.net, b.root-servers.net, e.root-servers.net, f.root-servers.net, j.
Over the time it has been ranked as high as 243 899 in the world, while most of its traffic comes from USA, where it reached as high as 183 330 position.