Trade routes are established by merchants.
These are units on the map, and need to be moved to their destination. They could be caught/intercepted by other civs.
A city can only trade with cities in range (whatever that means) of the source city.
You can trade with both foreign civs and independent people, but not your own cities.
You can pillage trade routes.
In the video at 1h8 min:
These are units on the map, and need to be moved to their destination. They could be caught/intercepted by other civs.
A city can only trade with cities in range (whatever that means) of the source city.
You can trade with both foreign civs and independent people, but not your own cities.
You can pillage trade routes.
In the video at 1h8 min: