---
title: Channels and sub-channels
type: explanation
section: spaces
summary: A channel is one shared conversation inside a Space; a sub-channel sits under a channel and draws its members from it.
applies_to:
  clients: [web]
sources:
  - evolve-front-end/components/team-chat/page-nav/nav-room-groups.ts
  - evolve-front-end/components/team-chat/page-nav/nav-space-channel-groups.tsx
  - evolve-front-end/components/team-chat/dialogs/team-chat-room-settings-dialog.tsx
  - evolve-front-end/app/i18n/locales/en/team-chat.json
verified:
  at: 2026-09-04
  env: code
  by: content-lane-spaces
ttl_days: 45
related: [spaces/create-a-channel, spaces/what-a-space-is, spaces/you-cannot-post-in-a-channel]
aliases: [team-chat/rooms, spaces/rooms-and-channels]
---

A channel is one shared conversation inside a Space. Channels appear in the navigation column under **Channels**, and every message, pin, thread, and file belongs to exactly one of them.

A sub-channel is a channel created under another channel. Its members come from its parent's eligibility pool, and its classification cannot be looser than the parent's. Sub-channels appear indented beneath the parent, with **Collapse sub-channels** and **Expand sub-channels** on the parent row.

## Membership: who can open a channel

Each channel is set one of two ways when it is created, and the setting is shown afterwards in **Conversation settings** as **Membership mode**.

- **Everyone in this Space** — everyone who belongs to the Space can open the channel automatically.
- **Invite only** — only people who are added can open it.

## Posting: who can write in it

**Conversation settings** also carries **Who can post**, with two values: **Everyone in the channel** or **Space admins only**. The second turns the channel into an announcement channel; everybody else can read it but the composer shows **Only Space admins can post here**.

## Groups: how channels are arranged

A Space administrator can sort channels into groups under **Space settings**, on **Channels & groups**, reached from **Manage channels & groups**. A group is a heading only: **Groups organize channels only. They do not create a channel.**

Separately, you can arrange your own copy of the list. The position control on a channel row offers **Move earlier** and **Move later** and needs no special rights, because it changes only your view.

## Archived channels

**Archive conversation** keeps the history and makes the channel read-only: **Members can still review the conversation history, but new messages and changes will be disabled. The conversation will be removed from the active channel list.** An archived channel is marked **Read-only archive** and stays searchable. Only channel owners and admins can archive one, and archiving cannot be reversed from Spaces.

## Channel types you may see

New channels created from Spaces are always of type **Channel** and classification **Internal**. Older or system-created channels can carry other types, shown in **Conversation info**: **Private channel**, **Decision channel**, **Incident**, **Protocol**, **Model run**, **Study**, and **Dataset**. The type changes the labelling, not the way you post.

## Related

- [Create a channel](/help/spaces/create-a-channel)
- [Add people to a channel](/help/spaces/add-people-to-a-channel)
- [You cannot post in a channel](/help/spaces/you-cannot-post-in-a-channel)
- [What a Space is](/help/spaces/what-a-space-is)