Light-emitting diodes is a research area and technological concept centred on semiconductor devices that exhibit electroluminescence, emitting photons when an electric current passes through a p-n junction under forward bias. This field investigates the fundamental physics of radiative recombination in semiconductor materials, the development and characterization of novel material compositions and heterostructures to optimize quantum efficiency and emission spectrum, and the engineering of device architectures for enhanced performance and diverse applications. Key characteristics studied include energy efficiency, specific wavelength emission, durability, and miniaturization, with significant implications for advancements in solid-state lighting, displays, and optoelectronics.