You start on a bare island in the void and build outward from a tree, a chest and a cow. When you create an island you pick its size, solo, duo, trio or squad, and the limit is enforced: a full trio island will not let a fourth player in, even by invite. Every island gets its own nether and end, sits 400 blocks from its neighbours, and has a 50-block protected area other players cannot touch. Island levels and player warps are running. The network has not opened yet, so there is no population.
The other modes
BedWars
Four maps are built, but the arenas are not set up, so no match can start yet.
playablePrison
Mine, rank up from A to Z, claim your own cell. Three currencies and one boss.
playableCreative
Claim a 64x64 plot, build with unlimited blocks, keep it protected.
playableSurvival
Claim land, build an economy, trade with other players. PvP is on.
playablePvP
1.8-style combat: no attack cooldown, sword blocking, old golden apples.