A distributed hash table (DHT) is a distributed storage system that functions similar to a hash table (in that it provides a key-value storage), but with special distributed properties (decentralisation, scalability, replication, sharding) and trade-offs inherent in their design.
DHTs are widely used in practical real-world distributed systems, such as in:
- BitTorrent, a peer-to-peer distributed file sharing protocol.
- Dynamo, Amazon’s NoSQL DHT designed for high-performance and eventual consistency.