An aggregator is a website or program that collects related content from other sites and displays it or links to it. Aggregators reduce the time needed to check websites for updates by delivering new content directly through RSS feeds. They allow users to be notified of new updates from sites they are interested in through a single program instead of visiting each site individually. While aggregators provide a convenient way to stay informed, they have some disadvantages like a lack of images, unclear source identification, and potential increased server loads from readers preferring full articles over summaries. Aggregators can be useful tools for language teachers to efficiently monitor student blog updates and progress outside of class.