Yes, in your back office you will see a tool for sending public messages, either as instant notifications, or messages that have been scheduled in advance.
You can also send group messages to a segment of your users (i.e. just exhibitors, speakers, moderators, attendees, or organizers). What’s more, your message can include links to encourage people to directly navigate to other areas of the event.
These messages can be viewed once or remain in the notification history of each user: it’s up to you, the organizer!