What do the three principles of architecture mean?

Architects still follow the three basic principles of architecture put forward by the ancient Roman architect Vitruvi two thousand years ago, namely, practicality, firmness and beauty.

Although there are many types of buildings, including residential buildings, shops and other civil buildings, public buildings such as libraries and conference halls, entertainment buildings such as cinemas and concert halls, industrial buildings such as warehouses and workshops, religious buildings such as temples and churches, and memorial buildings such as tombs, they have different practical functions and different proportions of practical components and artistic components, but they must be practical, three-dimensional and beautiful. Generally speaking, any building should be the unity of material function and aesthetic function, practicality and aesthetics, technology and artistry.