The Corporation is a dedicated-server-only extension of the Company system, also introduced in 0.7.5:
"You can create a Corporation in a Dedicated server that has its own Vehicle list and Budget, which allows it to keep running while owner is offline."
How it differs from a Company
Company — tied to the owner's vehicle list and presence.
Corporation — maintains its own separate vehicle roster and treasury. Operations continue around the clock on a persistent server even if every member is logged off.
Why this matters
Corporations are the structural backbone of long-running community trucking outfits, logistics groups, and taxi fleets on dedicated servers. They're what allows a "company" to actually feel like a business rather than a player's vehicle locker.