DAG-CBOR is a codec that implements the IPLD Data Model as a subset of CBOR, plus some additional constraints for hash consistent representations. DAG-CBOR also adds a "link" type using a CBOR tag, to bring it in line with the IPLD Data Model.
DAG-CBOR is a codec we recommend using. It has very complete mapping to the IPLD Data Model; it's binary and length-delimited (meaning it's generally very effecient to parse); and it's widely supported through the IPLD ecosystem.
See the DAG-CBOR specifications for details.