Using the interplay between the polymer matrix elasticity and the strong response of embedded magnetic nanoparticles to the external magnetic field, Magnetic Gels, or ferrogels, can serve various potential applications, ranging from artificial muscles, actuators, and micromachines to biomimetic energy-transducting devices. A manifestation of this coupling can be observed in the deformation of a macroscopic ferrogel body in a uniform or gradient magnetic field. However, any application of these materials is based on the profound knowledge of their microstructure and on the ability to control and design them on various levels. Experimentally there are two possible ways of embedding magnetic nanoparticles into ferrogels, either by trapping them physically in the hydrogel, or by chemically connecting polymer chains to the particle surface. The different trapping mechanisms are expected to strongly affect the macroscopic behaviour of ferrogels. In general, the number of control parameters, whose role might turn out to be crucial in this micro-macro relation, is rather large, and the problem of the investigation of the control parameter space is hardly feasible experimentally, but can be successfully elucidated by the computational and theoretical multiscale modelling, where the effect of different factors can be studied separately on various scales (coarse-grained simulations or mesoscale modelling).