@pratik Sorry for the late reply, I meant to answer back then but forgot about it. rssCloud enables feed readers (like the Micro.blog timeline) to get real-time notifications when a feed updates. This is nifty for people subscribing to the feed: they don't have to wait minutes or hours to see new posts – they will show up instantly.
For this to work, the feed reader and the feed publisher have to implement support for rssCloud. The Micro.blog timeline has support, but Micro.blog-hosted blogs don't.