An aggregator is a software, software application or service accessible on the web that automatically collects updated publications from a number of predefined web sites. An aggregator connects to these sites on a regular basis and collects all recently addes content. Aggregation can save you a considerable amount of time since you don’t have to check your favourite links each and every time for updates.
The good thing with aggregators is that they allow users to be informed about the updates of their favourite sites, simply by opening a single window.
What is content syndication / Syndicate
Syndication is the supply of material to different aggregators.
To authorize syndication on your blog, go to the "Configure" section and add the "Syndication" module.