TechStarz

We can define RSS more technically as a lightweight, topical, metadata and syndication format. Let us look into each feature to get a vivid picture:

Lightweight:
This is a very important feature looked upon by many users as one of the
reasons to prefer RSS tool. RSS is very small, in the sense – it requires less
space, usually less than a hundred kilobytes of space. RSS files are XML
documents, which can be written using any text editor (Word, notepad,
emacs, vi etc) very easily.

Topical:
RSS highlights what you think is important on your page and that would be
the contents seen by the other readers. For example, if you are a news
organization, you may want to focus on the latest headlines, if you are a
businessman you may want to showcase about your products or if you are a
publisher you may want to throw light on your latest book releases.

Metadata:
Metadata is the information about your data. You can embed details about
your data in your RSS file. For example, who wrote the article you are
highlighting or how often your RSS file wil be read to see if you have added
any information.

Syndication:
As we have already seen that it is to present a snapshot, in a specified
formatted file, of what you consider most important about your site at the
moment.