.

Also question is, how big is a Minecraft flat world?

The surface of the world is completely flat and at height y=4, with the exception of villages and other structures if they are enabled. Since the height limit (256) is unchanged, there is almost one-third more vertical height available to build above-ground structures as compared to a normal world.

Additionally, is the Minecraft world infinite? Minecraft worlds are not infinite, just really large. This is not how big Minecraft maps are though, this is just the largest map size that the game could theoretically create. The largest the map can be is 60,000,000 blocks, or 30,000,000 blocks from zero.

Beside above, what is the seed for a flat world in Minecraft?

You spawn in a plains biome, and next to it is a sunflower forest. This is completely flat for about 20 blocks and then gets slightly hilly. You spawn looking directly into a Sunflower patch. Directly behind you, the super flat area begins.

What shape is the Minecraft world?

Minecraft world is a cube, and we're living just on one side of it.