Atom is another XML syndication format that is used for creating web feeds. Atom Publishing Protocol (APP) is a simple HTTP-based protocol for creating and updating web resources.
Like RSS, Atom feeds are used for the syndication of web
content such as in Weblogs and headlines.
Feeds usually contain a
entries, which can be headlines,
full-text articles, links, summaries, or other content.
RSS, having arrived first to the syndication scene, was not perfect. Poor interoperability and incompatibility with earlier versions showed the need for a new standard. A faction of developers split off and formed Atom as a new syndication standard.
Here some ways that Atom attempts to distinguish itself from RSS:
Atom can distinguish between different content types such as HTML and plain text.
Atom defines itself within an XML name space.
Atom requires each entry to be unique by using a unique identifier.
Atom has separate elements for summary and content. Rather than simply providing a description, Atom attempts to distinguish between summary and content by providing the ability to include nontextual content in a summary.
Atom includes a standard for auto-discovery—a process by which news readers and browsers can automatically know whether a page supplies a feed.
for relative URIs—providing the ability to distinguish between
relative and nonrelative URIs.
Atom also uses the
xml:lang attribute rather than introduce its own proprietary language ...