The comment module is available in most of the modules (contacts, leads, opportunities, deals, listings…). It allows you to write comments related to a specific record.

Write some text and press the button

You can also mention a user from your team by entering @, the list of users will be displayed so you can select the one you want to mention. The mentioned user will receive an email notification.

You can also reply to an existing comment.

You can see the comment in the related record.

But also directly from your Home dashboard

Or accessing all the comments directly from the menu, inactivity section (depends on your permission).

In the comment module, you can filter comments by module, and users.