What is the difference between a rule and a filter?

A filter decides which articles you see: it hides the articles that match its conditions, keeps only those, or hides duplicate copies. A rule acts on the articles that match, tagging, emailing, notifying or translating them, and the articles stay in your feeds.

What each one does

A rule has a trigger under When, conditions under If and actions under Then, such as Assign tag, Send to email, Translate article or Push mobile notification. What actions can rules perform? lists them all. A content filter has one fixed effect, Remove articles or Keep articles, and no actions. A duplicate filter compares articles by the same URL, the same title or nearly identical titles. Rules and content filters share the same conditions. A filtered article is marked read and hidden for you, while a rule's actions leave the article where it is.

When they run and what they cover

For each new article, the duplicate filters run first, then the content filters, then the rules, so a rule never acts on an article a filter removed. A rule can watch the account, a folder, a feed, a tag, saved web pages, uploads, another rule, a Team channel or Intelligence reports. A content filter covers one feed or folder, and a duplicate filter a feed, folder, monitoring feed or the Newsfeed. A filter also applies to the recent articles already in its source when you save it, while a rule acts on new articles only, unless you click Run rule, which performs its actions on the latest 1,000. Turning a filter off brings back the articles it hid. Switching a rule off doesn't undo what its actions already did. A source holds one filter of each kind, while any number of rules can watch it.

Where to find them

Rules live in Automate > Rules and filters in Automate > Filters. The two work well together: a filter with Remove articles and Title contains "sponsored" on a news folder cuts the noise, and a rule on the same folder with Title or content contains your company's name and the action Push mobile notification alerts you to what's left. The blog post Streamline content discovery with filters and rules walks through such a setup.

Both are Pro features with separate limits: Pro includes 30 rules and 50 filters, content and duplicate together. What are filters? explains the two kinds of filter.