The booster ring is the core component of the HIAF accelerator system and is responsible for producing high-intensity, high-energy, and high-quality heavy-ion beams. It employs 4-D phase-space painting injection combined with a 3 Hz fast-ramping technique to accumulate and accelerate ion beams to the required intensity and energy. Key enabling technologies include a magnetic-alloy RF system, fast-ramping full-energy storage power supplies, and an extreme high vacuum system. BRing is capable of providing long-duration, uniform slow-extracted high-power ion beams, supporting a wide range of applications in nuclear physics, materials science, and biomedical irradiation.