Difference between the 4 Built in RSS Feeds?

Can somebody give me an explanation on the differences between the 4 different built in RSS Feeds and why / when I should choose one over the other? Why does WordPress incorporate 4 different ones instead of focusing on 1 universal one? The feeds include:

1) RDF/RSS 1.0 feed

2) RSS 0.92 feed

3) RSS 2.0 feed

4) Atom feed

WordPress RSS Feeds Codex

Solutions Collecting From Web of "Difference between the 4 Built in RSS Feeds?"

Feeds are not stored, WordPress generate them on request. That means that even if WordPress can generate 4 type of feed, that does not affect in any way performance, but gives the possibility to users to choose a format they like according to reader they are using: is not WordPress fault if there are different types of feed standard.

The WordPress preferred way is RSS 2.0, but if an user has different needs, WordPress allow to choose rdf, rss 0.92 or atom.

Of course you, as a site owner, can decide to support only one version, it’s as simple as:

add_action( 'pre_get_posts', function () {
  if ( is_feed() && ! is_feed( 'rss2' ) ) { // only support rss2
    header("HTTP/1.0 403 Forbidden");
    exit();
  }
});

The various versions of RSS contain increasingly complex information, with the RSS 2.* being the most up to date. Atom feeds are another competing method of syndicating content. In general, RSS Feeds are more commonly used, and are almost always used to distribute podcasts.

The Wikipedia article gives pretty good info. http://en.wikipedia.org/wiki/Rss

Why does WordPress incorporate 4 different ones instead of focusing on
1 universal one?

Because there is no such thing as a “universal” one. Different systems require different formats. Having support for multiple formats increases interoperability and is not a bad thing.