  Real-world networks such as the Internet and WWW have many common traits.
Until now, hundreds of models were proposed to characterize these traits for
understanding the networks. Because different models used very different
mechanisms, it is widely believed that these traits origin from different
causes. However, we find that a simple model based on optimisation can produce
many traits, including scale-free, small-world, ultra small-world,
Delta-distribution, compact, fractal, regular and random networks. Moreover, by
revising the proposed model, the community-structure networks are generated. By
this model and the revised versions, the complicated relationships of complex
networks are illustrated. The model brings a new universal perspective to the
understanding of complex networks and provide a universal method to model
complex networks from the viewpoint of optimisation.
