The finely stratified sphere model was used to calculate electromagnetic fields inside homogeneous and radially inhomogeneous spheres which are illuminated by electromagnetic plane waves. A complete picture of the internal fields is given for spheres whose diameters are comparable to the wavelength (alpha = 1.5 and 5, where alpha = 2 pi alpha/lambda is the size parameter of the sphere) and spheres whose diameters are much larger than the wavelength (alpha as high as 150), for coated spheres (spheres composed of a homogeneous core and a homogeneous shell) and gradient-index spheres (spheres with a continuous of refractive index), for spheres at states of morphology-dependent resonances (MDRs) and those at non-resonant states.