A short human readable title of the unit. This may be used by systemd (and other UIs) as a user-visible label for the unit, so this string should identify the unit rather than describe it, despite the name. This string also should not just repeat the unit name. "Apache2 Web Server" is a good example. Bad examples are "high-performance lightweight HTTP server" (too generic) or "Apache2" (meaningless for people who do not know Apache, duplicates the unit name). systemd may use this string as a noun in status messages ("Starting description...", "Started description.", "Reached target description.", "Failed to start description."), so it should be capitalized, and should not be a full sentence, or a phrase with a continuous verb. Bad examples include "exiting the container" or "updating the database once per day.".
Added in version 201.
Added in version 201.