This CSS Speech Bubble tutorial will teach you how to create a speech bubble using Cascading Style Sheets (CSS). You will learn how to create a basic speech bubble, as well as how to customize it to fit your needs. You will also learn how to use the :before
From Wikipedia
Cascading Style Sheets (CSS) is a style sheet language used for specifying the presentation and styling of a document written in a markup language, such as HTML or XML. CSS is a cornerstone technology of the World Wide Web, alongside HTML and JavaScript.