Islands is a gamemode where you spawn on an island that's almost submerged in water. You use your limited resources to survive!
The gamemode has many goals that can be achieved. Many players make farms and grinders in order to become rich and compete for island top. There are different leaderboards that you can compete for such as island levels, /quests (/q) and /mctop (these categories have payouts while the other leaderboards do not).
If you don't want to compete for leaderboards, you can play normally and build an island that you like. You can also take-part in the other features that the gamemode offers, such as defeating an Ancient Guardian boss, battling in an arena full of drowned mobs, challenging the community by fishing against them for prizes in the Mana Pond, gaining money by leveling up in jobs, and much more!
While Islands has many competitive features, the wonderful community is also here to lend a hand when you need it! Many features that this gamemode offers can be achieved by involving the community to help you along the way. There are separate guides to all of the features that are associated with Islands throughout the Wiki.