CAIRO VM

The Cairo VM is intentionally tailored for Validity Proof systems and is not constrained by the limitations imposed by the EVM (Ethereum virtual machine).

CASM

CASM (Cairo Assembly) is the machine code that the Cairo VM runs. CASM is translated to polynomial constraints that enforce the correct execution of a program. CASM is a key component in the ecosystem because regardless of what the user sends to the Starknet sequencer, what’s proven is the correct CASM execution.

CAIRO ZERO

Cairo Zero, released in 2020, introduced the world’s first Turing-complete language for creating STARK-provable programs, revolutionizing verifiable computation. Cairo Zero programs were compiled locally into CASM and then sent to the Starknet sequencer.

It is important to not that Cairo Zero V2 overcomes the limitations of Cairo Zero, promising safer, more efficient contract writing.

SIERRA

Sierra serves as an intermediate representation between Cairo and CASM. This additional layer ensures that user code remains provable in all cases.