Q. How do channels work in Office 365 Teams?
What are Channels?
Channels are separate hubs within a Microsoft Team 
. A Channel includes a separate conversation forum, a dedicated file space and a OneNote 
Notebook, which links to the main Notebook. Channels can be used to focus on specific topics or sub-projects within a Team.
Within each Channel, the team owner can add new Tabs to the Channel. These Tabs provide quick access to a wide range of resources including any Microsoft Office documents, YouTube 
videos or playlists, and Websites. An exhaustive list of resources is available when you add a Tab.
How do I create a new Channel?
To create a new channel follow the next steps:
- Click the ... (More Options) button next to the Team name, and select Add Channel.
- Fill out the Channel Name and Description (optional), then click Add.
How do I add people to a channel?
Every person in a Team automatically has access to all Channels within that Team. When you add a person to the Team they will have access to all Channels.
How do I add a Channel as a Favourite?
In order add a Channel as a favourite, click the Favourite Icon 
next to the Channel name, and it will remain visible in your Team list. If a Channel is not a favourite, a message appears in the Team list indicating more channels are available.
How do I get someone's attention in a channel?
If you type @ before the team members's name, they will receive a notification in Activity that you mentioned them. If you would like to get the attention of the whole team, you can use @team.
If you would like more detail about Microsoft Teams channels, you can visit Microsoft's guide here.