Application enclave
Intel SGX carves a small encrypted region — the enclave — out of one process. Only code inside the enclave sees plaintext; the OS, hypervisor and the rest of the app cannot. Powerful, but the app must be re-architected to split trusted from untrusted code.
Whole-VM TEE
AMD SEV-SNP and Intel TDX encrypt and integrity-protect an entire guest VM against the host hypervisor — no code changes, the whole OS runs confidentially. SEV-SNP came with 3rd-gen EPYC; TDX with 5th-gen Xeon. Distinct designs, comparable threat model.
The asterisks
AWS Nitro Enclaves is not SGX, SEV-SNP or TDX — it is isolation by the Nitro hypervisor, processor-agnostic, no in-use memory-encryption attestation of the kind SEV-SNP/TDX give. Confidential GPU extends the TEE boundary onto an NVIDIA H100. Read the footnotes.