Why star topology quietly won
Star topology dominates modern networks not because it's the most failure-resistant on paper -- a full mesh technically beats it there -- but because it offers the best practical balance: cheap to wire, easy to add or remove a device without disrupting anyone else, and simple to troubleshoot since a technician can isolate a fault to one cable or port. Its one real weakness, the central hub as a single point of failure, is manageable by simply buying a more reliable switch or router rather than wiring an entire redundant network.
How real networks blend more than one shape
Very few networks stick to one pure topology in practice. A typical office runs star-wired access switches in a tree hierarchy up to a core, then adds mesh-like redundant links between core switches so that no single cable failure can split the network in two. Understanding the basic shapes is what lets you recognize which trade-offs a given design is making.
Frequently Asked Questions
Which topology do real companies actually use?
Most mid-size and large organizations don't use a single pure topology. They typically build a hierarchical tree with access, distribution, and core layers, then add extra ('meshed') links between core devices for redundancy -- a hybrid design.
How do you fix star topology's single-point-of-failure problem?
By adding redundancy at the hub itself: duplicate core switches or routers configured to fail over automatically, backup power (a UPS) to survive outages, and, for critical networks, mesh-style extra links so traffic has more than one path to take.