Light-emitting diodes (LEDs) are attracting considerable attention around the world. Phosphor materials, as crucial color-converted components, play central roles in LED development. The demands for phosphor materials have become increasingly stringent over the past decades, from high brightness to narrowband emission or function-dependent spectrum engineering. Although substantial progress has been made for currently developed phosphor materials, simultaneously satisfying all requirements for high-level applications remains challenging. In this review, we aim to provide a comprehensive understanding of the development of phosphor materials in different generations and to elucidate the key designed mechanisms concerning the activators and the host structures to fulfill the aforementioned aspects. We highlight the developments in phosphor materials through the classification of demands for high luminescence, high thermal stability, narrowband emission for high color gamut, and broadband emission for near-infrared. We also focus on elucidating the key designed mechanisms of phosphor materials in different generations. Furthermore, future perspectives about micro-LED applications and nanoluminescent materials are provided. This study opens up an avenue for designing the luminescent materials of the future.