Within Teamwork Chat, you can interact with other users either in conversations or channels.
Conversations are intended to be brief interactions, such as a discussion about where to go to for lunch.
A channel is designed to be used over an extended period of time. Once you turn a conversation into a channel (by giving it a title), you give it more importance. For example, you might create a channel for each team in your company, such as Marketing, so they have a space to discuss related issues on an ongoing basis.
Both conversations and channel appear in the Timeline view of the sidebar, in reverse chronological order. The conversations or channels with the most recent messages will be at the top of the list.
For more information see: Creating a conversation or channel