Dolby technologies have dramatically improved the way we experience high definition movies. And dolby TrueHD produces audio that is identical to—and every bit as spectacular as—the master recording. It lets you experience the full potential of Blu-ray, and is even ready for the future. Here let’s discuss the definition and explanation of Dolby TrueHD.
Dolby TrueHD is a high definition digital-based surround sound format that supports up to 8-channels of surround decoding and is bit-for-bit identical to a studio master recording.
Dolby True HD is one of the two best surround sound formats found in today’s Blu-ray-based home theater systems. This lossless surround format is identical to the sound heard at the theater and comes across best via HDMI connection from Blu-ray players.
Dolby TrueHD is a lossless audio format, which means there is no fidelity lost when encoded onto Blu-ray.
The only ways to get Dolby TrueHD with an HDMI connection to a receiver that can decode it, or with a 6-channel analog connection between a BLu-ray player with such outputs and a receiver with a multi-channel input.
The next step down in fidelity with Blu-ray players is Dolby Digital Plus, which is found on some Blu-rays and on some streaming titles from Netflix and some other streaming services.
For more details, refer to the Official Dolby TrueHD Page
Other Dolby Resources
Also, look at the other HD audio standard: DTS-HD Master Audio.
More details are here.