Android developers strive for exceptional visual experiences, with High Dynamic Range (HDR) offering more vibrant and immersive content. UltraHDR on Android provides HDR benefits while maintaining compatibility with Standard Dynamic Range (SDR) displays. The term HDR has been conflated with other visual fidelity features like wider color gamuts and increased bit depth. From an Android Graphics perspective, HDR primarily signifies higher peak brightness capability beyond conventional SDR. Understanding HDR requires knowledge of color components: bit depth, transfer function, and color gamut. Bit depth determines color precision, while the transfer function maps pixel values to luminance, accounting for human visual non-linearity. Color gamut defines the range of reproducible colors, with wider gamuts enabling richer images. Myths suggest HDR offers more vibrant colors and contrast, but these are often achievable with wider color gamuts or specific video profiles, not solely HDR. HDR does not inherently offer higher bit depth, as this is also tied to specific video formats. Ultimately, HDR's core defining characteristic is higher peak brightness, representing a greater brightness range than SDR.