Status Bars
The new home for Visual Studio documentation is Visual Studio 2017 Documentation on docs.microsoft.com.
The latest version of this topic can be found at Status Bars.
Status bars give your application a place to display messages and useful information to the user without interrupting the user's work. Typically displayed at the bottom of a window, status bars have "panes," which include "indicators" and a "message line." The indicators give the status of such things as SCROLL LOCK, whether macro recording is turned on, and so on. The message line on the status bar can display information about program status or about a toolbar button or menu item that the user is pointing to with the mouse.
Create a status bar in your program by selecting the Initial Status Bar option in the MFC Application Wizard.
What do you want to know more about
Creating a new status-bar pane (Updating the text of a status bar pane)
Making a status-bar pane display text (Updating the text of a status bar pane)