WordPress 5.1.1

   WordPress is a content management system based on PHP and MySQL that is usually used with the MySQL or MariaDB database servers but can also use the SQLite database engine.

PHP 5.5.19

   PHP: Hypertext Preprocessor is a general-purpose programming language originally designed for web development.

Character Encoding :UTF-8

   This website is using UTF-8 character encoding in HTML , character encoding is used to represent a repertoire of characters by some kind of encoding system.

Apache 2.4.23

   The Apache HTTP Server, colloquially called Apache, is free and open-source cross-platform web server software, released under the terms of Apache License 2.0. Apache is developed and maintained by an open community of developers under the auspices of the Apache Software Foundation.

Vary Header Accept-Encoding

   The Accept-Encoding request HTTP header advertises which content encoding, usually a compression algorithm, the client is able to understand. Using content negotiation, the server selects one of the proposals, uses it and informs the client of its choice with the Content-Encoding response header.

WordPress DNS Prefetching

   DNS prefetching is an attempt to resolve domain names before a user tries to follow a link. This is done using the computer`s normal DNS resolution mechanism