Kleinberg's small-world phenomenon

Kleinberg's small-world phenomenon suggests that in many networks, such as social or communication networks, most nodes (people or places) are connected through surprisingly short chains of acquaintances. He showed that the way connections are formed—especially when they include a mix of local links and some long-distance ones—makes it possible to find short pathways between any two nodes efficiently. This explains why, despite vast sizes, individuals can often reach others through just a few intermediaries, highlighting the importance of network structure in enabling quick and efficient connectivity across large, complex systems.