A guide to optics, laser physics and engineering in the context of laser materials processing, aimed at upper-level undergraduate students. It describes light propagation at different scales, before discussing fundamentals of laser physics, including laser generation, beam characteristics and laser properties. Following this, active media, amplifiers and common laser types are used as a bridge between laser physics and laser engineering. It then advances into specific engineering topics, covering high resolution laser processing (including ultra-short pulses, laser-processing microscopes) and laser-matter interaction (predominately linear interactions).