I tried using the babelfish translator and I still didn't understand what that was.
Valheim is an open world game, meaning: once you enter the game world, you can run to wherever you want and do whatever you want. It's set in one of the many worlds of the afterlife from Norse mythology.
Every world is differently because they are procedurally generated, using complex computer formulas to generate the layout of the terrain. That process begins by using a "seed."
Each world has various biomes - types of terrain - such as Meadows, Black Forest, Swamp, Plains, Mountains, and Oceans. Each biome has its own set of flora and fauna (the "bio" in "biome"); many of the latter of which want to kill you.
In addition to the kill or be killed aspect, players can harvest resources from the various biomes. These are used to build weapons, armor, potions, etc.
There is also the building aspect of the game.
Oh, the building aspect of the game.
Considering the game only gives you a few dozens shapes of various materials, you can do quite a bit. I've built a dock to park my longship. The dock has a number of green-flamed torches that serve as piloting lights. I have a bonfire at the end of a jetty to serve as a lighthouse. I also built a warehouse, smithy, a farm with crops and a sty for tamed boar, and - of course - a Viking longhouse. You can even use the game physics to your advantage. I built a set of 4 kilns in a raised platform. Beneath each set of 2 was a ramp. The ramps angle towards each other so when the kilns drop the coal they produce it rolls down the ramps into a central bin for easier collection.
Basically, when I'm tired of getting my ass kicked by the critters in the latest biome I just chill building-up my Viking village.
Overview of the game:
https://youtu.be/9OP3pxFVYOwAn example of what some people (not me) are able to build:
https://youtu.be/gUa-nT2DuI8