An ATOM file is a Syndication format for the structure of Atom feed and entry documents. Similar to .RSS files, ATOM file format is an XML-based syndication format that is a standard for publishing content. An ATOM file is used for web feeds that allow software programs to check for updates that are published on the website. It contains entries that can be of different types such as headlines, full-text articles, excerpts or links to content on a website
Applications that can open ATOM files include Apple Safari.
ATOM File Format - More Information
ATOM files are stored and published in the popular XML file format that is a universal format for exchange of information. It was developed as an alternative to RSS keeping in view the limitations and flaws of RSS file format.
Types of Atom Documents
Atom Entry Documents - It is an XML document that consists of a single item of information, know as entry, for the Atom feed. It has an atom:entry element that contains a number of child elements. The content of an Atom entry can be plain text, HTML, XHTML, or another IANA (Internet Assigned Numbers Authority) media type.
Atom Feed Documents - It is an XML document that provides metadata about an Atom feed and one or more entries for the feed. When a client makes a request for information from the feed, the feed document is generated by the server which includes a number of Atom entries to fulfil the request.
Atom Collection - It is a special kind of Atom feed document that contains the URLs of Atom entries that are available to be edited.