Really Simply Syndication (RSS) is a standard web format that allows you to subscribe to web content when new content is available. RSS allows content to come to you, rather than you visiting a particular web site. There are many research-related web sites that provide an RSS feed to their content, such as professional organization sites, publisher sites, newspapers, library sites, and blogs. RSS feeds can include text-based information as well as podcasts (for example, lectures) and vodcasts (for example, YouTube videos).
In order to read RSS feeds, you need an RSS feed reader or aggregator that manages your subscriptions. One highly-recommended feed reader is Feedly, which works as a website and is also available as an Android and iOS app. Many web browsers like Chrome, Safari, and Firefox have built-in RSS feed readers, or allow add-ons to be added.
Your citation management program may also provide RSS capabilities. For example, Zotero supports integrated RSS feeds.
Check out your professional organization's web site for RSS feeds. Many scholarly organizations are making news or conference information available via RSS. If their website includes blogs or an "in the news" page, look for an RSS feed.
Many more government agencies are providing RSS feeds to frequently updated or changing content. (As an example, see the National Institute of Mental Health RSS feed.)
All news web sites, such as CNN, provide RSS feeds for rapidly changing content posted to their sites.
But in all likelihood, the best method to discover RSS feeds is to visit the web sites you routinely visit and look for the RSS icon or some text indicating RSS availability (such as ).