Way long ago in a land far far away the Schwinn Varsity was utilized as an all-road machine. We rode over hill and over dale, paved, unpaved, single track, two track, and no tracks at all.
"All-road" like "gravel" are marketing terms used by the industry to denote to the consumer a particular bicycle is not subjected to the confines of 25mm or narrower tires, and that the bike can comfortably traverse the terrain the trusty old Schwinn Varsity was so capable of doing.