Blockstars are fully-rigged, animatable 3D models, delivered to owners as .fbx files.
Each Blockstar is a truly unique individual, with a unique personality (modeled on the Myers-Briggs framework), a unique skill set and an (initially) unknown Potential Ability, which is unlocked & discovered through gameplay. The various personality types determine not just how skilled that particular Blockstar can be - but they also determine how compatible that individual Blockstar is with every other Blockstar in the ecosystem, and therefore how good their Chemistry is going to be as members of the same band.
Each Blockstar is player-owned as a unique NFT on the Solana blockchain, and is minted with a random, programmatic, pre-determined starting set of characteristics of varying degrees of rarity. However, unlike most other programmatically-generated NFT drops that we have all become so familiar with, Blockstars don't just have varying degrees of cosmetic rarity. Blockstars also incorporate rarity into multiple other facets, which have an impact on gameplay as well as how "useful" a given Blockstar will be.