Reference
A working glossary for blockchain execution.
Use these definitions while reading BlockVM guides. Terms are scoped to runtime architecture rather than token markets or general blockchain promotion.
- ABI
- Application binary interface: the encoding and calling convention used to pass values between programs and external tools.
- Bytecode
- A compact instruction representation consumed by a virtual machine rather than directly by a physical CPU.
- Calldata
- Read-only input supplied to a contract or program call; in EVM systems it commonly carries a function selector and encoded arguments.
- Determinism
- The property that the same valid inputs and pre-state produce the same outputs and post-state across honest implementations.
- Execution trace
- An ordered record of steps, calls, state accesses, or constraints produced while a program runs.
- Gas
- A metering unit used to bound and price computational, storage, and data resources.
- Guest program
- The program executed inside a sandbox or zkVM whose behavior is constrained or proven by the runtime.
- Host function
- A controlled capability exposed by the runtime to guest code, such as storage access, hashing, logging, or cross-contract calls.
- Linear memory
- A contiguous byte-addressed memory region used by a WebAssembly module during execution.
- Opcode
- A single virtual-machine instruction, such as add, load, store, jump, call, or hash.
- Precompile
- A protocol-defined function exposed at a special address or identifier, often for cryptographic operations that are inefficient in ordinary bytecode.
- Prover
- The system that computes a cryptographic proof that an execution or statement satisfies specified constraints.
- Receipt
- A record of a transaction result or, in some zkVM systems, a proof-bearing artifact that authenticates public outputs.
- Revert
- A controlled execution failure that rolls back state changes in the relevant call frame and may return error data.
- Sequencer
- An actor or mechanism that orders transactions for a rollup or other execution environment.
- State root
- A cryptographic commitment summarizing the current state data structure after a transition.
- Storage
- Persistent state associated with a contract, account, object, or key-value namespace.
- State transition function
- The deterministic rule that maps a pre-state and ordered inputs to a post-state and outputs.
- Validity proof
- A proof accepted only when a proposed state transition satisfies the encoded rules.
- WASM
- WebAssembly, a portable binary instruction format often embedded in blockchain runtimes behind chain-specific host functions.
- zkVM
- A virtual machine integrated with a zero-knowledge proof system so correct program execution can be verified from a proof or receipt.