NEM is a Blockchain-based peer-to-peer cryptocurrency and a development platform. You can’t define NEM without mentioning its innovative consensus algorithm a Proof-of-Importance algorithm.
Every user of the NEM Blockchain that holds more than 10,000 XEM has his or her “importance score.” Once a user gets to that threshold, every coin on the account and every transaction that was linked to the account will improve his or her importance score. Miners with a higher importance score are more likely to get a reward from mining. The POI system is designed this way to stimulate NEM users not only to have XEM coin, but also to perform transactions with it.
NEM also provides such features like Messages included in transaction that can be used for secure communication, and multi-signature transactions that protect users from hackers and secure the community-held funds.