Rationally designed plasmonic nanostructures enable precise modulation of light–matter interactions by confining and enhancing electromagnetic fields at the nanoscale. By tuning parameters such as material, shape, size, and spatial arrangement, these systems can be optimized for specific optical responses, offering vast potential across nanooptics. Their ability to control light at subwavelength scales has positioned nanoplasmonics at the forefront of applications including biosensing, surface‐enhanced Raman spectroscopy, photovoltaic light harvesting, optoelectronics, and nanomedicine, driving transformative advances in science and technology. Despite their strengths, plasmonic systems suffer from significant optical losses due to the intrinsic properties of metals like gold and silver. These losses, primarily from Ohmic damping, convert optical energy into heat and limit performance in some applications. Nevertheless, plasmonic structures retain a key advantage in scenarios requiring strong field confinement, where dielectric systems typically fall short. This review focuses on areas where plasmonic nanostructures remain particularly effective, such as sensing, surface‐enhanced spectroscopy, emission modulation, and nonlinear optics. Selected examples are presented to illustrate fundamental principles and recent developments, offering a comprehensive guide for researchers exploring nanoplasmonics in these targeted applications.