Ch. 5: RSS, XML, and Atom: What’s the Difference?

You are browsing a blog site one day, and then you saw this orange button that says “RSS”. You then checked a news site, and then saw an orange button that says “XML”. Then you saw some more sites that have RSS links. Now, you wonder, what are these things all about?

What follows are basic information regarding RSS, XML and Atom.

What is an XML?

• General Definition – XML stands for Extensive Markup Language. It is the standard markup language used to define various types of data. It is created to enable data sharing among various systems patched by the Internet. The language format is formalized, to allow modification and validation of files regardless of prior knowledge of the document form.
• XML Features – Before the birth of the XML files sharing files among different programs and platforms was difficult because of the use of binary system in encoding. In an XML file, characters (the fundamental unit) are sequenced in an allowed serial pattern. Word processors also made XML maintenance and authoring easier, since it will be dealing with characters, not bits.
• Uses of XML
1. XML is used to represent a lot of data, especially lists, records and trees- the basic forms of data structures.
2. It can also be used to communicate human languages that are written because of the Unicode support.
3. The XML format is also employed in data processing and storage.
4. Pros and Cons – The XML format is a universally accepted format. It also does not depend on a specific platform for it to execute. It also employs a hierarchical code structure that is compatible with most of the document formats.

However, XML is limited by bandwidth. In the case of PDA and cellular phone technology that uses XML, files are compressed.

Now, what then is RSS?

• General Definition – RSS, which stands for Really Simple Syndication, is a set of web feed formats that use XML to deliver information.
• What are the uses of RSS feeds? – RSS feeds are used to give updates to users regarding site contents without having to actually check the site. This can be done by delivering the full content of the update, or by sending a link, or by defining the metadata that composes the file. A lot of sites like web logs, pod casts and news sites use RSS feeds.
• What are the benefits of RSS feeds? – The information that can be seen in RSS feeds is simpler than the source web site. That is why it is easier for users to view the important items.
• RSS formats – The standard RSS formats are:
1. RSS 1 or RDF which includes the following versions: RSS 0.90 and 1.0
2. RSS 2 which includes RSS 0.91, 0.92-0.94 and 2.0.1

How about Atom?

Issues were raised regarding the RSS 2.0 format and its incompatibility problems. That is why a third standard of syndication was born.

The atom format started in June of 2003. It was adopted by the Internet Engineering task Force or IETF. This format was made to solve the shortcomings of the RSS versions that were released.

RFC 4287 states the proposition of Atom’s standardization.

• Strengths – Atom supporters claim that the strength of Atom relies on:
1. Use of standard features of XML;
2. The presence of a payload container capable of handling various content types.

• Uses of Atom – Atom, like any other syndication formats, is used on sites that update periodically. These items include web logging, advertisement, marketing, news and bug reports.

Atom and RSS: What’s the deal?

Atom included features that are not present or mandatory in RSS such as:

• XML schema
• auto discovery
• XML name space
• unique global ID
• payload container
• separate content and summary entities
• openness to modification and standardization

Now that you know the definitions of XML, RSS and Atom, you will never have to wonder why these things are places in certain websites.

Ch. 4: How to Design and Install Blogs Ch. 6: Collect RSS feeds, Update Easily!

RSS, XML, Atom News