A zkVM is a virtual machine whose execution can be cryptographically proven. This enables a prover to convince a verifier that executing a program produces some result, without the verifier having to repeat the execution themselves.
zkVM is an acronym for zero-knowledge virtual machine. While some zkVMs do use zero-knowledge proofs, others use succinct cryptographic proofs which do not have the zero-knowledge property.
Examples
editTinyRAM[1]
Cairo
RISC Zero
SP1
Jolt[2]
Miden
Triton