MPC Wallet
A wallet in which a private key is split into shares held by different parties and never exists whole in any one place.
Multiparty computation lets the shareholders jointly produce a valid signature without ever reconstructing the full key on a single machine. The result is one ordinary signature on chain, so an MPC address is indistinguishable from any other address and costs no more in network fees. Custodians and institutional platforms favor the approach because it works identically across blockchains and because policy rules, such as spending limits and approval workflows, can be enforced around the shares. The tradeoff against multisignature is transparency: multisig rules are visible and enforced on chain, while MPC rules live in the operator's systems.
In practice
An institutional platform can require approvals from staff in different regions before their key shares combine to sign, without that policy being visible on the blockchain.
The common misunderstanding
MPC and multisig are not the same: multisig is enforced and visible on chain, while MPC splits the key off chain and produces a single ordinary signature.