The essential technology for high-definition video streaming is bandwidth and efficient compression algorithms. High-definition video requires large amounts of data to be transferred quickly, which is facilitated by high bandwidth. Additionally, video encoding formats like H.264 and H.265 employ compression techniques to reduce file size while preserving quality. Streaming protocols such as RTMP and DASH are also crucial, as they allow for adaptive streaming and seamless playback across various devices, greatly enhancing the overall viewer experience.