What's the difference between Team channels and Team tags?

A Team channel is for sharing and discussing: a Team admin picks its members, a shared article comes with a note and comments, and the channel's members are notified. A Team tag is for filing: every Team member has it, anyone can create one and tag articles with it, and tagging notifies nobody.

Who is in it and who creates it

A channel is invite-only: only Team admins create channels and add members. A Team tag reaches every member of the Team, and any member can create one, from New Team tag in the Team sidebar, from Create tag in Manage Team > Content > Tags or straight from an article's tag menu.

How articles get in

An article goes into a channel with Share with Team (press S), with an optional note, or through a rule action. An article gets a Team tag with Add tags (press T), with Add tags in the bulk actions bar or with a rule's Assign tag action.

Discussion and notifications

In a channel the note becomes the first comment, and members comment and mention each other with @. When an article is shared, the other channel members get an in-app notification and a push, and comments and mentions also send emails. A Team tag has no note or comments of its own, and tagging an article sends no notification to anyone.

Who can undo it

The person who shared an article stops sharing it. Any member can remove a Team tag from an article, and that removes it for everyone, but only the tag's creator or a Team admin can rename or delete the tag itself.

Find them in the Team sidebar

Both live in the Team sidebar, under Channels and Tags. A Team admin can give a channel output feeds and forward its articles to Slack or Microsoft Teams. A Team tag has an Output feeds switch and a pin that shows it in your sidebar.

Plans

Both come with the Team and Team Intelligence plans. What is a Team channel? and What are Team tags? describe each, and What is the difference between a Team folder and a Team channel? compares channels with folders. The feature page Share one set of sources with your whole team and the blog post Introducing new collaboration features for Inoreader Teams have more.