Short answer:

ISO 18092 (NFC) introduces Peer-to-Peer communication mode for arbitrary binary data exchanges. This mode is missing in ISO 14443 (Contactless Card)

More details:

ISO/IEC 18092 (NFCIP-1 Near Field Communication - Interface and Protocol Specification), is based on ISO/IEC 14443 but has a critical difference. It utilizes different command protocol to replace Part 4 of ISO/IEC 14443. It also includes two communication modes, active and passive, which allow an NFC device to communicate with other NFC devices in a peer-to-peer mode as well as with ISO/IEC 18092 based NFC tags (cards).

Within the two modes of communication there are three modes of operation defined in ISO/IEC 18092:

• Read/Write: In this mode, the NFC enabled phone can read or write data to any of the supported tag types in a standard NFC data format
• Peer-to-Peer: Two NFC-enabled devices can exchange data over some sort of custom binary protocol
• Card-Emulation: While NFC-enabled phones can act as a reader when in contact with tags, in this mode, the phone can also act as a tag (contactless card) for other readers (POS terminals)

Specifically, the NFC Forum states that in card emulation mode, NFC-enabled phones can support the contactless card EMV payment application requirements specified in EMV CCPS v2.0 and embodied by American Express ExpressPay 2.0, MasterCard PayPass 2.0 and Visa payWave 2.1.1.

Therefore, if the NFC device operates under the specifications of ISO/IEC 18092 in card emulation mode, it should be interoperable with a reader/writer (POS terminal) that operates under the specifications of ISO/IEC 14443.

However, ISO/IEC 18092 also defines a peer-to-peer mode where two devices can exchange data (i.e. a card acting as a reader). There is no such current equivalent defined in ISO/ IEC 14443 and therefore these NFC devices would not be interoperable with devices operating under ISO/IEC 14443.

So, if you plan to operate in Peer-to-Peer mode, for example, implementing your very own custom binary data exchange protocol over NFC, you may need to use ISO 18092 compliant device / chipset