LPCM is uncompressed, similar to your wav files. That's the format recording studios use when processing digital audio files. DTS-HD and DolbyTruHD are compressed files, though lossless, designed mainly to be stored efficiently in such medua as HD-DVD and Blu-Ray and even DVDs. Think of them as zipped LPCM files. When DTS-HD/MA and DolbyTrueHD get uncompressed by being decoded, they are unzipped and you get LPCM files. Similarly, DD and DTS are lossy compression codecs that when decoded, also end up as LPCM files.
Now having said that, LPCM files can also have different resolutions like 192/24, 96/24, 88/24, 48/24, 48/16, 44/16 (which is CD-quality), etc. DD and DTS tracks are decoded and become LPCM files at the standard 48/16. DTS-HD/MA and DolbyTrueHD get decoded at 96/24 LPCM. LPCM tracks in BD and HD DVD discs are at 48/16. Movies are more commonly mastered at 48/24 LPCM.