This guide is for core block type development which uses code and stores blocks at /src/BlockType/. This guide is for internal development team use or for developers interested in the structure of the core codebase. If you are looking to build block types using the Block Type Editor (UX) look for this separate topic under documentation (@TODO link to block type editor ux guide).
Block Type names are CapitalCased the same as other PSR classes. The main block type class will be a single PHP class with the same name as the block.