**6. Conclusion**

This chapter collects a variety of discussed and summarized studies advocating the use of plant extracts, oils, rare earths, and amino acids as corrosion inhibitors of metals and alloys. These inhibitors also present certain challenges, but they offer many advantages, and they remain the most ideal and promising alternative as they are generally synthesized from natural and non-toxic products, which increases their availability and effectiveness in terms of environmental and human safety.
