From http://www.w3schools.com (Copyright Refsnes Data)
Multimedia is pictures, sounds, music, animations and videos.
Modern web browsers have support for many multimedia formats.
Multimedia is everything you can hear or see: texts, books, pictures, music, sounds, CDs, videos, DVDs, Records, Films, and more.
Multimedia comes in many different formats. On the Internet you will find many of these elements embedded in web pages, and today's web browsers have support for a number of multimedia formats.
In this tutorial you will learn about different multimedia formats and how to use them in your web pages.
The first Internet browsers had support for text only, and even the text support was limited to a single font in a single color, and little or nothing else.
Then came web browsers with support for colors, fonts and text styles, and the support for pictures was added.
The support for sounds, animations and videos is handled in different ways by different browsers. Some elements can be handled inline, some requires a plug-in and some requires an ActiveX control.
You will learn more about this in the next chapters.
Multimedia elements (like sounds or videos) are stored in media files.
The most common way to discover the media type is to look at the file extension.
When a browser sees the file extensions .htm or .html, it will assume that the file is an HTML page. The .xml extension indicates an XML file, and the .css extension indicates a style sheet.
Picture formats are recognized by extensions like .gif and .jpg.
Multimedia elements also have their own file formats with different extensions.
You will learn more about media file extensions in the next chapters.
From http://www.w3schools.com (Copyright Refsnes Data)