Chat is another way to communicate with other users in text form, alongside Teams and Channels.
Chat is quite different from communication within teams in that messages are not chained, but run as a single stream. In chat, you can easily have a conversation between two people, but you can also start a chat conversation between several people. Scheduled meetings and their chat messages are also stored on the chat page.
The chat page is recommended to be used primarily for private messages and one-to-one conversations. In other cases, Teams and their channels are a better place to communicate with a larger group. However, you can use chat to communicate with more people; for example, if you need to communicate with a manager and a secretary at the same time on an HR issue, you can start the conversation with the two people in Teams chat instead of an email chain.
To start a new chat on the chat page, click on the "New Chat" button next to the search bar.