Definition, synonyms and related words
Initialism of Rich Site Summary / Really Simple Syndication (“mechanism to follow updates on other websites such as news, music, blogs, etc.”).
"Many users subscribe to an RSS feed to automatically receive updates from their favorite news sites and blogs."
In plain English: RSS is a way for websites to automatically send you their latest updates without you having to check them manually.
"I subscribed to his RSS feed so I would receive instant updates about his latest blog posts."