When the Internet was born and was making its first steps into the lives of the people, most websites were simple and not very content-rich. This was due to the fact that most people relied on dial-up Internet connections, which didn't offer high speeds. With the advance of the technologies in the years to follow, the connection speeds were significantly increased, which allowed for an advance in both the design and functionality of the websites, most importantly the ability to provide video streaming directly from the website.
The MP4 standard
The name "MP4" comes from the Moving Picture Experts Group-4. It is a standard for the compression of both video and audio files, introduced in 1998. It quickly became popular for its features and the low processor power needed to play the files encoded in this format. It quickly became the de-facto standard for online streaming and broadcasting. While a file encoded in the MP4 format can contain both audio and video, there are separate extensions for just-audio MP4 files.
Today, the use of MP4 is standard among website designers. It allows them to add a short video clip to their site, advertising their products and special offers or making an overview of their company. The most common use of MP4 files is when they are wrapped with a flash player, adding controls for forwarding and pausing the video clip. This is available with almost every web hosting plan.
The MP4 file extension
MP4 does not have a defined file extension. Due to the fact that it allows for having both video and audio content in one file, there are several file extensions:
The .mp4 and .m4a file extensions
The default file extension for MP4 encoded media is “.mp4”. However, since files ending with .mp4 could contain both video and audio, it was almost impossible to distinguish if a file was a video clip or an audio track. This is why, the .m4a extension was created. Files with the .m4a extension contain only audio tracks. This format got very popular due to the fact that it was used for all audio tracks sold by the Apple iTunes store.
The .m4b file extension
Another MP4 file extension includes the .m4b file extension, which is similar to the .m4a extension. Both of them designate audio files, but the .m4b extension is mostly used for podcasts and audio book files, since files encoded with this extension support additional metadata and can allow for the playing to continue from where it was last stopped.
The .m4r extension
This extension was created by Apple especially for their iPhone. Files with this extension also contain only audio tracks and are used for Apple iPhone ringtones. With the increasing popularity of Apple's phone, .m4r files are getting more popular.