FLoC / FedCM / Privacy Sandbox
Also known as: privacy sandbox, floc
Google's umbrella project of replacement APIs meant to enable advertising without third-party cookies.
The Privacy Sandbox bundles several proposals: Topics (interest signals), Protected Audience (on-device auctions, formerly FLEDGE), Attribution Reporting (conversion measurement) and FedCM (federated sign-in). FLoC was an early proposal, withdrawn in 2022 after criticism.
The goal is to keep ad targeting and measurement working after third-party cookies are gone, while shifting more computation on-device. Whether the trade-off actually improves privacy depends on how many APIs you enable and what fingerprinting continues alongside them.