DoubleClick is a provider of digital marketing technology and services. Companies come to DoubleClick for expertise in ad serving, media, video, search and affiliate marketing to help them make the most of the digital medium.
nginx [engine x] is a HTTP server and mail proxy server written by Igor Sysoev.
Meta descriptions are HTML attributes that provide concise explanations of the contents of web pages. Meta descriptions are commonly used on search engine result pages (SERPs) to display preview snippets for a given page.
The http-equiv attribute provides an HTTP header for the information/value of the content attribute. The http-equiv attribute can be used to simulate an HTTP response header.