Cascading Stylesheet (CSS) language main goal is to allow a web developer to paint and style elemenets of the web page with specific features, such as positioning, colors, decorations, shades, responsive style for mobile devices and more.
The web developer will set a property name and a value to declare the style changes.
The browser will implement the properties set by the developer, and "paint" or style the HTML components.
In CSS, properties and values are case-insensitive by default.
We "select" the paragraph (p) and style it with green color using CSS:
In CSS3 we use the /* */ sign to define a comment, comments are ignored by the browser, they are like notes, CSS comments help us and other web developers to understand the HTML and CSS code, even long time after we have created it.
Everything between the CSS comment opening tag and the closing tag will be marked in grey and will be ignored by the browser, you can also define a multi line CSS comments: