Desfire EV2 and NTAG216 are both 13.56 MHz NXP Mifare products, but they have quite different structure and memory capacity. Desfire EV2 has 8K memory, while Ntag216 has 888 bytes.
Desfire chips are suitable for more complicated applications that require higher level of security and bigger memory size.
Ntag chips are perfect to be used as a tag on mobile phones, for writing small data or for the simple access/authentication applications. It also has 7-byte UID that makes this chip secure enough for the targeted use cases.
For more detailed information about each type of chip please check following datasheets: