CSS, Cascading-Style Sheet, is a markup language used with HTML used to design the user interface of a website. The style is applied to the markup language throughout the same sections of similar parts. CSS is not a programming language. CSS was first published at W3C in 1998 but was created by Hakon Wium in 1994.
HTML, Hypertext Markup Language, and not a programming language, it is a markup language. It was developed in 1980 by physicist Tim Berners-Lee but the browsers server software was not introduced until 1990.
<h1>This is a Heading</h1>
<p>This is a paragraph.</p>
PHP is a programming language which is a server-side scripting language. It was designed for web development but it also can be used as a general-purpose programming language. It was developed in 1994 by Rasnus Lerdorf who named it “Personal Home Page Tools.”
echo “What does the PHP programming language look like? “;
Java is a general-purpose computer programming language that is concurrent, class-based, and object-oriented. It was specifically designed to have as few implementation dependencies as possible. It was developed in 1995 by James Gosling at Sun Microsystems (Sun was acquired by Oracle)
Next we need to look at the Chrome “Inspector” and the Architiecture of WordPress.