SPF

   The Sender Policy Framework (SPF) is an email-authentication technique which is used to prevent spammers from sending messages on behalf of your domain. With SPF an organisation can publish authorized mail servers.

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.

WordPress 5.5.5

   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.

Apache

   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.

schema.org micro-markup

   Schema.org is a collaborative, community activity with a mission to create, maintain, and promote schemas for structured data on the Internet, on web pages, in email messages, and beyond.

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.

Meta Description

   A meta description is a 160-character snippet, a meta tag in HTML, that summarizes a page`s content. this website is having meta description of the following : Infor Jeunes Laeken est un centre d'accueil et d'information pour les jeunes sur le droit scolaire et le droit social.

XFN 1.1

   XFN is a technical term that is an acronym that stands for “XHTML Friends Network.” This is primarily used by websites that want to create a series of referral links between other websites in order to boost SEO ratings.

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.

Gzip Content-Encoding

   The Content-Encoding entity header is used to compress the media-type. When present, its value indicates which encodings were applied to the entity-body. It lets the client know how to decode in order to obtain the media-type referenced by the Content-Type header.

Chunked transfer encoding

   Chunked transfer encoding is a streaming data transfer mechanism available in version 1.1 of the Hypertext Transfer Protocol (HTTP). In chunked transfer encoding, the data stream is divided into a series of non-overlapping "chunks"

Twitter Cards

   With Twitter Cards, you can attach rich photos, videos and media experiences to Tweets, helping to drive traffic to your website.

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

PHP 5.6

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

Youtube

   YouTube is an American online video sharing and social media platform launched by Steve Chen, Chad Hurley, and Jawed Karim in February 2005. After Google, YouTube is the most visited website worldwide, with over one billion monthly users.