Cabotage is closely linked to two of the most restrictive and difficult-to-obtain freedoms of the air:
Eighth Freedom (Consecutive Cabotage)
This allows an airline from State A to carry passengers between two cities in State B, but only as part of a larger service that originates or ends in State A.
For example, a Spanish airline flying the Madrid-Brasilia-Rio route could sell tickets for the Brasilia-Rio leg if granted eighth freedom rights.
Ninth Freedom (Pure or Standalone Cabotage)
This is the most complete form of cabotage, granting an airline from State A the right to operate flights entirely within State B, without connecting to or from their home country.
An example is an Irish airline operating the domestic Valencia-Malaga route in Spain.
EXTRA: Do you know how many airlines fly from Malaga airport?