We report on a thorough X-ray study of irradiation induced defects in iron. Single crystals were irradiated at 4.6 K with reactor neutrons and at 90 K with 2 MeV electrons. After irradiation and subsequent thermal annealing, we measured the defect induced diffuse scattering of X-rays (Huang scattering) and the small angle scattering of synchrotron radiation. Simultaneously, lattice parameter and electrical resistivity changes were measured. The single defect properties are determined from low dose electron irradiated samples and yield the lattice distortions, i.e., the volume change and defect symmetry as described by the force dipole tensor. Excellent agreement of the experimental results with calculated values from literature is observed. After neutron irradiation, defects are correlated within displacement cascades. The correlations for vacanciesand interstitials are described by a spatial correlation volume. These results are compared with computer simulations usingthe Marlowe code. During thermal annealing the irradiation induced defects agglomerate at characteristic temperatures and we observe changes in the spatial correlations of the defects. There is a clear difference between electron and neutron irradiated samples concerning defect recovery in stage 1.