The left hand pane of IceWarp Server's Administration Console shows the "nodes" which allow access to all the Settings, Options, Domains and Accounts on the server.
Some of these nodes are replicated on the toolbar but you can also Customize your toolbar if you wish to place any nodes that you use often allowing you to access them quickly.
You should also note the leftmost icon on the toolbar, which is for Remote Server Administration, which allows you secure access to a IceWarp Server from a remote location.

Some nodes have sub-nodes. These can be expanded and collapsed by clicking the plus (+) or minus (-) sign next to them, or by double-clicking the node.
Selecting a node affects the contents of the right hand pane, which may itself split into two panes.