Minecraft wiki entry for Texture_Pack, associated text: A texture pack was a collection of files that were used to change the in-game textures of blocks, items, mobs and the GUI. They were .zip files that had various PNG images in them and a text document named pack.txt. The native resolution of Minecraft's textures were 16×16 (measured pixels in block height and width). 32×32, 64×64, 128×128, 256×256, 512×512, and 1024×1024 textures were referred to as "HD".