how do voxel games like minecraft use so little resources

Hi i have knowledge in 2d game design and c# but Ive decided to try unity to develop a game similar to mine-craft for fun, What I don’t understand is how Thousands of blocks are able to be rendered in game without using that much resources. What methods does minecraft use to increase performance?

  1. There are no individual blocks, many blocks in a grouped in a “chunk”, that makes things easier
  2. The 3d model of a chunk is updated everytime the chunk is changed, only the surfaces are given a quad, the inside faces don’t get geometry generated for them.

After that its just a matter of managing memory for the chunks intelligently (maybe even unloading chunks you know wont be modified soon while keeping the 3d model)

Creating a “real” cube for every block in the game is the worst possible solution.