DISTRIBUTED HASH TABLE
Distributed Hash Table (DHT) is a distributed storage system. In DHT, the value is stored amongst a set of distributed nodes which introduces both unique features and complexities.
Unique features include decentralization (no central node or server), fault-tolerant (values are redundant), scalable (node number can even be millions).
Complexities: like all distributed system operations, it needs to maintain data consistency. Operations of adding, deleting, updating are influencing more than one node which incurs additional costs compared to that of a traditional hash table.