Chests are a kind of lootboxes in Trove. You can obtain them during the gameplay. From them you can mostly obtain resources for crafting, upgrading, etc.
Each chest is unique in its own way, and have unique items.
Chaos Chests can drop different resources, flux and various mounts.
Trove of Wonders are considered a test of your luck, either you will get absolutely nothing, or one of the two dragons with a chance of 1 in 8000 named Ganda, the legendary bird that can walk on the air, that makes her fastest flying mount with knight subclass ability.