Magnetic field in the inner near-Earth space

We review the development of modern models of the magnetic field of Earth's inner magnetosphere, from the selection of experimental results to the approximation and presentation of the model output data. In particular, we discuss all principal sources of the magnetic field, their description in various models, and approaches to parameterizing the field. We briefly recall the history of the study of Earth's magnetic field and discuss modern-day and earlier experimental data used in model building and the underlying core mathematical tools. The main features of the majority of modern models describing Earth's magnetic field in the inner magnetosphere are discussed.