Plasma electrolytic oxidation (PEO) emerges as a promising surface engineering technology for an array of light alloys, including aluminum, magnesium, and titanium. Its flexibility and growing importance in automotive, aerospace, biomedical, and many other industries highlight its versatility and potential. This electrochemical process uses electric discharges to create multi-component oxide coatings, giving materials outstanding physical, mechanical, and chemical properties. These properties include improved wear and corrosion resistance, biocompatibility, thermal stability, and beneficial dielectric characteristics. This presentation explores the properties of PEO coatings, with a focus on their strategic design through the customization of the PEO process to attain specific properties for different applications. The primary emphasis lies on enhancing corrosion and wear resistance, as well as biocompatibility.