From Black Desert Wiki
The world of Black Desert is a beautiful and wondrous place full of monsters and lands to explore. Half of the world is covered in a Desert. Two major countries are in control of most of the livable areas.
There are two major warring countries in Black Desert. They are Republic of Calpheon and Kingdom of Valencia. Calpheon is located on the west and Valencia is located towards the east in the dry desert areas. Both countries are fighting for Black Stones which are minerals located between the two countries. Valencia calls the desert, the "Red Desert" because of the countless bloodbath that have stained the area.
There are various towns and cities scattered across the map. Some towns live peacefully while others have been overtaken by monsters.
Black Desert is a seamless open world. Other than a few instances in the game (mainly story instancing according to Pearl Abyss), you can travel to and fro. There is no map loading.