Collimation is the process of aligning rays or particles within a beam to become parallel, thereby significantly reducing angular divergence. As a fundamental methodological concept in optics, radiation science, and particle physics, it involves investigating the principles, techniques, and instrumentation used to control beam directionality and minimize spatial spread. Its key characteristic is the production of highly parallel beams, which is significant for enabling precise spatial resolution in imaging, accurate targeting in therapy, and controlled interaction volumes in scientific instrumentation.