RSS stands for Really Simple Syndication - a web feed format for publishing frequent updates of site content such as news, blog posts, etc.
Publishers benefit from RSS feeds because this lets them syndicate their site content automatically. Readers benefit from web feeds by getting timely updates when something new is posted on their favorite websites.
If you want to enable RSS feeds in your phpBB forum, you can install the Smartfeed mod. This mod is available for both phpBB2 and phpBB3 and will provide you with a user-friendly interface to manage the way your forum topics are added to the feeds.
For detailed information on how to install the Smartfeed mod, you can refer to the mod's official page.
