The method of creating various nanoparticles (NPs) using different metals or metal ions and plant extracts is regarded as an environmentally friendly method in nanotechnology as an alternative to physical and chemical methods. NPs, when made through green synthesis, have a wide range of applications in agriculture, biomedical, and environmental sciences because they use fewer harmful chemicals. This review presents the principles and methods for green synthesis of NPs, as well as a comprehensive study of NP synthesis from plants and their recent applications. Plant extracts with low environmental toxicity, including magnesium oxide, zinc oxide, silver, and gold, were used to synthesise NP. [ABSTRACT FROM AUTHOR]