Cascading Style Sheets is a style sheet language used for describing the presentation of a document written in a markup language such as HTML.
PHP stands for "PHP: Hypertext Preprocessor". It is a widely-used Open Source general-purpose scripting language especially suited for web development. It can be embedded into HTML. The main goal of the language is to allow web developers to write dynamically generated web pages quickly, but you can do much more with PHP.
Many dynamic websites require a back-end database. The database can contain information that the web pages display to the user, or the purpose of the database might be to store information provided by the user. In some applications, the database both provides available information and stores new information.
MariaDB is a community-developed, commercially supported fork of the MySQL relational database management system, intended to remain free and open-source software under the GNU General Public License.
WordPress is a free and open-source content management system written in PHP and paired with a MySQL or MariaDB database.
AMP is an open source HTML framework developed by the AMP Open Source Project. It was originally created by Google as a competitor to Facebook Instant Articles and Apple News. AMP is optimized for mobile web browsing and intended to help webpages load faster.