Hashing is a technique used to efficiently determine data storage locations, particularly crucial in data streaming applications and distributed systems. It involves converting data into a fixed-size output through hash functions, and storing this data in hash tables for quick retrieval. While basic hashing can lead to inefficiencies due to data collisions and rehashing requirements when system changes occur, consistent hashing offers a solution by organizing data storage across a conceptual ring of servers. This method minimizes the data that needs to be moved when servers are added or removed, ensuring efficient load distribution. Consistent hashing is particularly useful in distributed systems like content delivery networks, where it helps balance requests and maintain performance under server failure conditions. Examples of applications employing consistent hashing include naming services and systems like PubNub, which handle large-scale, reliable data exchanges by leveraging this technique along with other backend optimizations.