Community Connect lets you conduct 1:1 communication in a chat format with Threaded Messages.
From the Messages tab, when you click into an individual conversation you'll see all the messages sent for a particular contact. Your messages (or system messages) are shown on a white background and your contact's messages are shown on a green background. Another point of differentiation is the box next to the message. Your messages are shown with:, and the contact's with: .
In order to send a message to that contact, enter your message in the 'compose message' box and press enter. This is a quick and easy way to conduct 1-off communication with clients.