What's the relationship between the C2PA and the Content Authenticity Initiative (CAI)?

C2PA writes the technical standard; the CAI is the community that promotes it and builds the open-source tools that implement it.

• C2PA — the standard-setting body (a coalition incl. Adobe, Microsoft, Intel, BBC, etc.). It defines the spec: how manifests are structured, signed, and verified.
• CAI (Content Authenticity Initiative) — founded by Adobe in 2019; the advocacy + implementation arm. It drives adoption and provides open-source SDKs and tools (compliant with the C2PA spec).
• Content Credentials — the consumer-facing brand name for the provenance data the system attaches.

Analogy: C2PA is like the body that writes the HTTP specification; the CAI is like a coalition shipping the open-source web servers and browsers that speak it.

Tip: Standard = C2PA. Movement + tooling = CAI. Label on the file = Content Credentials.