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A feed, also known as RSS feed, XML feed, syndicated content, or web feed, is frequently updated content published by a website. It is usually used for news and blog websites, but can also be used for distributing other types of digital content, including pictures, audio or video. Feeds can also be used to deliver audio content (usually in MP3 format) which you can listen to on your computer or MP3 player. This is referred to as podcasting, which is a form of on-demand audio content.
You can receive content automatically by subscribing to a web feed. When you subscribe to a web feed, you set the interval at which Internet Explorer or iTunes (examples of programs that have the ability to function as feed aggregators) will check the website for updates. Once you've set an interval, the aggregator will automatically download the most up-to-date web feed list.