This chapter provides a concise historical overview of the main scientific and technological developments that shaped up modern plasma electrolytic oxidation (PEO) technology, which is used to deposit high-performance oxide ceramic coatings on the surfaces of light alloys. It further discusses current trends in the subject area including morphological refinement of PEO coatings on Al through application of pulsed bipolar polarisation waveforms, transition to the soft sparking PEO mode and ongoing work on digitalisation of PEO processes based on application of intelligent polarisation signals incorporating process diagnostics segments. Finally, it discusses recent advances in fundamental understanding of the electrochemical behaviour of PEO coatings under pulsed reversed polarisation conditions.