zulip/templates/zerver/help/about-streams-and-topics.md

# Streams and topics

In Zulip, streams determine who gets a message. Topics tell you what the
message is about.

| Conversation model | Who gets it | What it's about
|---|---|---
| Zulip | Stream | Topic
| Email | Mailing list | Subject line
| Slack/IRC | Channel | -

One big difference is that Zulip organizations typically have more streams
than they would email lists, and Zulip topics are much shorter than email
subject lines. Here is what it looks like in Zulip.

![](/static/images/help/streams-and-topics.png)

Streams and topics are the hardest part of Zulip to grasp, but also the most
rewarding part of using Zulip.

If you ever find yourself stuck on writing a topic, just pretend you're
sending an email, with the topic as the subject line. After a few days
you'll get used to a more Zulip-y way of doing things, and your topics will
naturally become shorter (2-3 words is optimum) and take less thought to type.

## Why topics?

Learning how to chat with topics has a bit of a learning curve, anywhere
from a few minutes to a few days. Why bother with something so
complicated?

The short answer is that most users spend many hours a day on chat. A little
investment up front pays huge dividends in access to a more powerful
communication paradigm.
A longer answer is [here](https://zulipchat.com/why-zulip).

## Replying

When replying to a message, the stream and topic are conveniently
pre-filled. Click on a message to reply, or type `r` to reply to the message
under the blue box.

## Further reading

* [Setting up streams for your organization](/help/getting-your-organization-started-with-zulip#create-streams)

* [Browsing and joining streams](/help/browse-and-subscribe-to-streams)

* [Public and private streams (stream permissions)](/help/stream-permissions)

* Browse the articles under **Streams & topics** and
  **Stream management** on the left sidebar.