HyperText Markup Language, or HTML, is the primary language in which web pages are written. Generally more simple than other programming languages like PHP and JavaScript, HTML uses a series of tags to define, design, and format web pages.
The tags are the elements of HTML and are typically surrounded by angle brackets and form the content of a web page. They usually are paired together and enclose text, thus formatting the text according to the specific tag. They are called opening or start tags and closing or end tags. There are some HTML tags that do not come in pairs and are used as a single tag to represent data.
HTML documents are read by a web browser which translates the tags into what the web page should look like. The tags themselves are not displayed by the browser but it uses them to determine the content of a web page. Web sites use HTML as building blocks for the sites. Images, videos and other digital media can be embedded into web pages using HTML. HTML can also be used to create forms that are interactive and allows users to enter data into web sites. Headings, paragraphs, lists, links, quotes and other items are also defined in HTML so as to format for the documents. Scripts written in such languages as JavaScript can be inserted into a web page by HTML and serve to produce animation or other effects.
Cascading Style Sheets are also a part of HTML and are used to define the look and feel of a web page. They separate the content of a document from its presentation which can provide more control and flexibility in the appearance of a web page. They also serve as a template for the design of web pages as they can be shared to reduce the repetition of using HTML for formatting purposes.