What does it mean to "favorite" or "pin" a community?

Favoriting or pinning a community on Reddit is a way to elevate it within your navigation interface, making it faster to access without having to scroll through your full list of subscribed communities. The distinction between the terms depends on context: on Reddit, the functionality is technically called "favoriting" and is represented by a star icon, but users colloquially refer to it as pinning because the effect is to pin certain communities to the top of your sidebar navigation. On the desktop website, each community in your left-sidebar subscription list has a small star icon that appears when you hover over the community name. Clicking that star marks the community as a favorite, and it immediately moves to a Favorites section that appears above the alphabetically sorted list of all your other subscriptions. This Favorites section persists at the top of the sidebar for easy one-click navigation. You can favorite as many communities as you want, and the Favorites section grows accordingly. On the mobile app, favoriting works similarly: when viewing a community page or the communities list in your side menu, you can tap a star icon or select "Favorite" from the community's options, which moves it to the top of your community navigation for quick access. Custom feeds can also be favorited using the same mechanism, allowing you to keep your most-used custom feeds alongside your most-visited individual communities at the top of the navigation. The practical value of this feature is significant for users who have subscribed to hundreds of communities across many topics — the full sidebar list can become unwieldy and slow to scroll through. Favoriting between five and fifteen communities that you visit every day or every session creates a personal dashboard at the top of your navigation while still preserving access to your full subscription list below. Unfavoriting is done by clicking the star again, which removes the community from the Favorites section and returns it to its alphabetical position in the full list.