Once echoing has started, the rest of the command is echoed immediately as you type it. This behavior is designed to give confident users fast response, while giving hesitant users maximum feedback. If you issue a command that cannot be executed, XEmacs may print an error message in the echo area. Error messages are accompanied by a beep or by flashing the frame. Any input you have typed ahead is thrown away when an error happens.
Some commands print informative messages in the echo area.
These messages look similar to error messages, but are not announced with a beep and do not throw away input. Sometimes a message tells you what the command has done, when this is not obvious from looking at the text being edited. Sometimes the sole purpose of a command is to print a message giving you specific information. The echo area is also used to display the minibuffer , a window that is used for reading arguments to commands, such as the name of a file to be edited. When the minibuffer is in use, the echo area displays with a prompt string that usually ends with a colon.