Edited sentence: Air cargo is commonly known as freight.Aircraft were first used for carrying mail as cargo in 1911, but eventually manufacturers started designing aircraft for freight as well.Most nations own and utilize large numbers of cargo aircraft such as the C-17 Globemaster III, for airlift logistics needs of such operations.Such very large aircraft also employ quick loading containers known as ULDs much like containerized cargo ships.There are many commercial aircraft suitable for carrying cargo such as the Boeing 747 and the bigger An-124, which were purpose built to be easily converted to a cargo aircraft.There are many firms which collect freight from a shipper and deliver it to the customer such as Nightfreight or UPS