The Battle.net chat screen interface is made up of four areas.
At the top is the ad banner bar.
To the left is the chat log area. It displays the channel you are in and text in the chat log for your chat session.
To the right is an information area. It is used to display the profile for people in the chat room and serves as an interface area for the buttons on the right.
Along the bottom is a members area. It is a graphical representation of the people in the channel.
Send
This button will send the text you enter as a public post to the chat area.
Whisper
This button will send the text you enter as a private message to the person highlighted in the members area.
Help
This button will display a list of Battle.net commands in the chat log area.
Squelch
This button will mute the output of the person highlighted in the members area.
Unsquelch
This button will restore the output of the person highlighted in the members area.
Emote
This button will send the text you enter as an emote to the chat area.
Create
This button will open the create game dialog in the information area.
Join
This button will open the join game dialog in the the information area.
Channel
This button will open the channel dialog in the information area.
Ladder
This button will opens the list of Diablo II PVP ladder rankings in the information area.
Quit
This button will close the Battle.net session and return you to the main menu screen.