Crowfall's gamespace is divided into multiple worlds that each encompass a different purpose or level of risk and reward. Currently there are three bands: the Eternal Kingdoms, God's Reach, and Campaigns.
God's Reach is the first world you'll log your characters into and begin the New Player Experience; a tutorial that also quickly levels your character. The NPE will take you through a variety of zones with varying level ranges of mobs for you to level your character and learn the game's mechanics from level 1 to 17-18, you can level the rest of the way to 30 by grinding mobs in the corresponding zone to your current level range. There is no PvP in God's Reach proprer, everyone is on the Balance faction here.
Although these NPCs and Monsters don't pose a lot of threat, attract too many or find one that's too high level and you can still die, resulting in loss of durability on your equipment, but unlike the higher risk bands you do not drop your inventory in this band. Because of the low risk, the gear and other resources that drop off of these NPCs and Monsters are low quality.
You won't find rare NPC or Monster spawns in God's Reach.
Harvestable resources will only be between Rank 1 and 5. From these you will get mostly Common quality materials, some Uncommon quality, and very little Rare quality.
The Infected is a setup as a practice faction campaign in the God's Reach band of worlds where the scores contantly reset. This means your inventory is still safe but you can now PvP with the opposing factions outside the faction temples. When you first enter the Infected, you will select a faction (Sun, Moon, or Earth). You can team up with others in your faction to roam, siege, and whatever other activities you desire.
As far as rewards go, there are some Captain and Chief ranked NPCs, as well as Elder animal monsters. These enemies drop higher quality gear and other resources such as uncommon quality Minor Disciplines and Necromancy additives.
The Harvestable Resources in the Infected range between Ranks 5 through 7. Harvesting these results in a fair amount of Uncommon quality resources, some Rare quality, and very little Epic quality.
Crowfall's answer to player housing, Eternal Kingdoms (EKs) are Unique worlds set up by a particular player that either be public or private. There are no Monsters or killable NPCs that spawn in Eternal Kingdoms. Only Poor quality basic harvestable resources can be acquired here (Knotwood, Cobblestone, and Slag).
The owner of the EK can enable PvP. In such a case, everyone can attack everyone else, though you may still form parties of up to 5 people. If you are killed in an EK your inventory is lootable, so be careful. Your account vault is accesible from anywhere inside an EK so make sure to store your stuff if you intend to PvP.
Besides free for all PvP, the primary purposes of the Eternal Kingdoms is to act as centers of Commerce. The owner (and players they allow) can place buildings, crafting stations, and vendors.
The Dregs is one of the Campaign types. In this World, your Guildmates are your only friends. World PvP is enabled between Guilds and the Siege hours are taken very seriously. If you die in the Dregs, you lose your inventory, which can be picked up by other players. You keep your equipped armor, weapons, and tools.
Currently, campaigns last anywhere from a few days to several weeks, rotating through different seasons that affects the NPC spawns and your Harvesting ability.
This is the highest risk World, meaning you could potentially reap the best rewards. In addition to Captains and Chief NPCs, you will also find Kings, who drop even better gear and disciplines. In addition to Elder animals you will also find Alphas and Ancients, who will drop more items and the highest quality Necromancy additives.
Harvestable Resources in the Dregs are between Ranks 8 through 10. Harvesting these results in a fair amount of Rare quality resources, some Epic quality, and very little Legendary quality. You NEED Advanced Tools to harvest these resources.
The Dregs also uses a unique scoring system called Divine Favor, every season has a set of cards with different critera for guilds to compete and receive points. Whichever guild has the most favor at the end of the campaign wins.