In Slack, teamwork and communication happen in channels. A channel is a single place for a team to share messages, tools and files. Read on to learn all about how to create, join and use channels to collaborate with your teammates.

All about channels

• Channels can be organised by team, project or whatever else is relevant to you.
• Team members can join and leave channels as needed.
• Threads allow for focused and organised side-conversations within channels.

Create channels

Channels can be organised around anything, and a workspace can have as many as needed – there’s no limit! They're available for all subscriptions: Free, Standard, Plus and Enterprise Grid.

 Public channels

• They're open for all members to join, and anything posted is searchable by others.

• By default, all members of a workspace (but not guests) can create public channels. Workspace owners can change this permission and limit channel creation to certain roles.

 Private channels

• They're for discussions that shouldn’t be open to all members, so you must be invited to join one to view it in Slack.
• By default, all members of a workspace (including some guests) can create private channels. Workspace owners can change this permission and limit channel creation to certain roles.

 Shared channels

• Shared channels let separate organisations work together in a single channel, each from their own Slack workspace. This feature is available on the Standard, Plus and Enterprise Grid subscriptions.
• Organisations can choose if they’d like a shared channel to be public or private for their workspace.
• All members (except guests) can send and accept invitations to share a channel. Depending on your workspace settings, the accepted invitation may need approval from an owner or admin before a channel is shared.

  Multi-workspace channels

• Multi-workspace channels connect separate workspaces within an Enterprise Grid organisation. This feature is only available for the Enterprise Grid subscription.
• Multi-workspace channels can be public or private.
• Org owners and admins can create multi-workspace channels within their organisation, and give members permission to do this.

Join channels

How members join a channel depends on the type of channel it is.

 Public channels

• Members can browse and join any public channel in their workspace(s).

 Private channels

• Members must be invited to join a private channel.

 Shared channels

• Whether the channel is public or private determines how members can join.

  Multi-workspace channels

• Whether the channel is public or private determines how members can join.

Use channels

While a workspace can have as many channels as needed, Slack works best when channel guidelines are in place, and certain best practices are followed.

Guidelines

• Every channel should have a clear topic and description.
• All channels in a workspace should follow established naming guidelines.
• Use message threads to keep in-channel conversations organised.

Best practices

• Transparency matters, so most conversations should happen in public channels so that they’re searchable by all members. Don’t worry – members can set channel-specific notifications and choose when to get notified or mute activity altogether.
• Maintenance is important: Archive unused channels when they’re no longer needed, or delete them entirely if you don’t want to preserve their history.
• Manage who can post with spaces dedicated to announcements, reviewing support tickets or showcasing your team's work. 
• If the nature of a channel changes, it can be converted from public to private, but not vice versa. For privacy reasons, private channels cannot be made public.