The goal of subnettingis to create a fast, efficient, and resilient computer network. As networks become larger and more complex, the traffic traveling through them needs more efficient routes. If all network traffic was traveling across the system at the same time using the same route, bottlenecks and congestion would occur resulting in sluggish and inefficient backlogs.

Creating a subnet allows you to limit the number of routers that network traffic has to pass through. An engineer will effectively create smaller mini-routes within a larger network to allow traffic to travel the shortest distance possible.
Organizing a network in an efficient way is crucial for large firms and those companies seeking to expand technologically. IP addresses can be kept geographically localized meaning that a subnet can be used for specific staffing structures to maintain efficiency and order.