The Status Bar

The Status Bar is located at the bottom of your application and serves the following purposes:

To display brief information relating to a specific icon or menu item.
To show the progress of commands.
To display/set the position of the mouse in XYZ space in the currently open file.
To display if a command is currently running.
To show the read status of the currently open file.
To see or set numlock, scroll lock and caps lock statuses.
To view the viewplane distance between subsequent mouse clicks.
To view the current azimuth and dip values of the last clicked point.
To pick a custom cursor for use in the primary 3D window.

The Status Bar is available in all windows.

More detailed information on some of the bar zones:

Messages

This read-only area displays prompt information when running commands, and provides information about the menu item or icon directly under the cursor (for icons, a tooltip will also be displayed).
Cursor Position

The XYZ location of the cursor is updated dynamically with mouse movement. In the Plots and Logs windows, as these are 2D viewports, no Z value is displayed.
Cursor Appearance

You can see the cursor that is currently in use in the primary 3D window here. By default, this is set to <none>, meaning a default cursor will be displayed. Double-clicking this section of the Status bar displays the Custom Cursors dialog, from which you can select an existing custom cursor or design one. More...
Quick Key Status

This area displays information relating to a recent quick key command. The information displayed will show the key combination, and the name of the command. If a key combination is typed that isn't recognised, the command name is shown as 'ambiguous'.
Snap Mode Status

The current snap mode is also displayed in the status bar. You can see if your Snap Mode is set to [GRID], [LINES], [NONE], [POINTS] or [SURFACE]. Double-clicking this part of the status bar displays the Snap to Mode screen.