A "message of the day" (motd) is a greeting message displayed after a successful login, just before a login shell is executed.
In Unix-like operating systems, the "message of the day" is a feature for sending common messages to all users. The message is shown after a successful login, just before a login shell is executed. Traditionally the motd has been preferred over sending e-mail to all users, as it allows for more efficient delivery, particularly in terms of disk space usage. The motd is usually stored in the file
/etc/motd, although some modern Unix-like operating systems, such as certain Linux distributions, have facilities for assembling the motd from a collection of scripts at login.