Many databases allow users to register for regular alerts to help them keep up to date on a topic.
RSS stands for "Really Simple Syndication", these feeds subscribe researchers to updates from databases/websites and are generally denoted by "RSS" or an image like:
Databases may provide an RSS Feed URL for each search and publication. RSS Reader software sends out links to subscribed researchers whenever new material, that meets their criteria, is added to the database.
RSS readers may be downloadable applications or web-based services that work inside a browser.
Some examples are:
Feedreader - free software you can download and install on your computer.
netvibes - web-based, free, easy to use.
FlowReader - a free, web-based reader.
Feedspot - free, easy to use, works in most browsers.