The winter is a biome that was added in the WINTER IS FINALLY HERE update. It covers about 2/3 of the map and is larger than the forest. The winter is much colder than the forest, and it is almost impossible to stay alive without using Cap and Scarf or fires. The winter is the stage for advanced players to obtain high tier resources, such as amethyst and the dragon heart. Summary: "The snow biome (AKA winter) is REALLY FLIPPIN' COLD! "
The advantage of the winter is that there are fewer players and bases than the forest, and players can focus on survival. Also, the winter contains all of the newly added resources which increases the player's power.
The winter is extremely cold and has mobs that are challenging to kill without the right technique and equipment. It is also limited in resources and planting seeds is disabled. Walking on snow decreases speed by 20%.
Even with a coat, the heat loss is about as much as wearing nothing during the night in the forest. Also, the 2 mobs: the polar bear and the arctic fox have a lot of HP and are very dangerous, as the biome is in general. Make lots of campfires, full gold tools, and try not to die!
In the winter there are supplies of every deposit. It should be noted that the trees inside of the Snow Biome will only give about 10-20 wood each, so it is a good idea to get as much wood as you can beforehand to make fires instead of relying on trees inside of the winter.
If there is no inventory space prior to entering the winter to hold extra gold for making diamond tools, there are large amounts available inside of the center of the biome to mine.
The only way to obtain food inside of the winter is by killing arctic foxes and polar bears for meat, but this is not recommended for inexperienced players who don't know how to kill them. A good idea to make sure that you have enough food for an expedition is to set up a farm in the forest for berries, and obtain at least 200-300 of them.