**6. Conclusions**

The nanoscale interaction dynamics and confinement of photons and electrons were depicted in this chapter, which served as fundamentals of nanophotonics. The foundation for modeling nanophotonic structures, as well as the methodologies used to tackle issues at the nanoscale regime, such as light propagation, scattering, localization, and multiscale problems, have been frequently discussed in terms of two forms of versatility. Nanophotonic structures are used in a wide range of applications, including nanomedicine, biomaterials, biotechnology as well as optical diagnostics, and they are the spark for the next forefront of economic development.
