nginx [engine x] is a HTTP server and mail proxy server written by Igor Sysoev.
PHP is a widely-used general-purpose scripting language that is especially suited for Web development and can be embedded into HTML.
The DOCTYPE is a required preamble for HTML5 websites.
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.
Meta Keywords are a specific type of meta tag that appear in the HTML code of a Web page and help tell search engines what the topic of the page is.