The deep forest is a dangerous place with wolves and goblins that roam the vast, unexplored terrain. There is only one outpost in Deep Forest, which is guarded by soldiers from Icemire who prevent goblins and wolves from entering the area. If you wander deeper into the forest, you may find portals to other realms that lead even further into the forest, where worse beings than goblins can be found.
A realm is a crafted area that can either be your private realm or an open realm where you can meet other players. Dungeons are procedurally generated areas associated with a realm that can usually only be entered by a few players per instance.