A feed is a list that updates itself
An RSS feed is a file on the web that lists a site’s latest items in a standard, machine-readable format. Each entry has a title, a short description, a date and a link. When the site publishes something new, the file is updated and the new item appears at the top.
The name is commonly expanded as Really Simple Syndication, though people often just say RSS. A related format called Atom does a similar job, and most readers handle both. The files are written in XML, a structured text format that software can read easily even though it looks cluttered to a person.
The key idea is that you do not have to visit a site to learn that it has changed. A program checks the feed for you and shows what is new.
How a feed reader works
A feed reader or news reader is an app that keeps a list of feeds you have subscribed to. At intervals, it fetches each feed, compares it with what it has seen before and shows only the new items. Some readers do this on your device. Others run as an online service that gathers feeds for you and syncs across devices.
Subscribing is usually just a matter of pasting the feed address into the app. Many sites advertise their feed in the page itself, so a reader can often find it from the ordinary web address. Where the feed link is not obvious, it is often found through a small icon or a page labelled feeds.
Because the reader asks for new items on a schedule, updates are not instant. The delay depends on how often the app checks and on the site’s own settings.
How podcasts use the same format
A podcast is essentially an RSS feed with audio attached. Each episode is an entry in the feed. The entry includes a special element, called an enclosure, which points to the audio file and states its type and size. The feed also carries information such as the show name, description, artwork, and episode titles and dates.
Notably, the feed does not contain the audio itself. It holds a list of addresses. When you play an episode, your app downloads or streams the file from wherever the publisher or their hosting company keeps it. Streaming audio over the web relies on the same ideas described in the guide to how streaming services deliver media, although podcast files are commonly plain downloads of a whole episode.
When you subscribe to a podcast in an app, you are really telling the app to watch that feed. The app checks for new entries, lists them and, if you like, downloads them automatically so they are ready offline. This is why a downloaded episode can play on a flight without any connection.
Why the same show appears in many apps
The big directories you see in podcast apps are mostly catalogues of feed addresses. They store the show’s information and a link to its feed, and the app does the actual fetching. Since the feed is an open format, the same address works in any app that understands it. That is why you can move between podcast apps and bring your subscriptions with you, often by exporting a small file listing your feeds.
This openness is the reason many listeners and publishers like the format. No single company owns the feed, and anyone can publish one. It also means that there is no single gatekeeper to rank or remove the show, though individual directories and apps still decide what they list.
There are exceptions. Some services offer shows that are available only inside their own app, sometimes behind a login or subscription. These may not be offered through an open feed at all. Other shows use private feeds for paying supporters, where the address is personal and should not be shared, because it works like a key.
What RSS offers beyond podcasts
For reading, feeds provide a calm alternative to checking sites one by one or relying on a social media timeline. A reader shows items in the order they were published, rather than in an order chosen for engagement. People use feeds for news sites, blogs, local notices, software release announcements and more.
Limits to be aware of:
- Some sites publish only a summary in the feed and require you to click through for the full text.
- Some sites no longer offer a feed.
- A feed shows what the publisher chooses to include, and not every site keeps its feed current.
- Feed readers vary in features, price and how they handle your data.
Privacy and feeds
Fetching a feed is an ordinary web request, so the publisher or host can see that something requested the file, and typically sees an address and the app used. Podcast hosts often count downloads to report audience size. Some podcast apps and online readers also keep records of what you subscribe to and what you listen to. This is similar in kind to the data discussed under online privacy, and the policy of whichever app you choose describes what it keeps.
Personal feed links, such as those for paid shows, should be treated as private. If one leaks, others may be able to use your access.
Getting started
To try a feed reader, choose an app, subscribe to two or three sites you already visit, and see whether the experience suits you. For podcasts, pick an app that lets you add a show by its feed address and export your subscriptions, so you are free to switch later.