Apple have published a
article about the different flavours of ProRes
All members of the Apple ProRes codec family support frame sizes up to 4K as well as SD, HD, and 2K at full resolution. The data rate of Apple ProRes varies based on codec type, image content, frame size, and frame rate.
Apple ProRes includes the following formats:
Apple ProRes 4444: This codec offers the best quality for 4:4:4:4 sources and for workflows involving alpha channels. It features:
Full-resolution, mastering-quality 4:4:4:4 RGBA color, perceptually indistinguishable from the original material with excellent multigeneration performance
Mathematically lossless alpha channel (up to 16 bits) with real-time playback
High-quality solution for storing and exchanging motion graphics and composites
A remarkably low data rate compared to uncompressed 4:4:4 HD (the target data rate is approximately 330 Mbps for 4:4:4 sources at 1920 x 1080 and 29.97 fps)
Direct encoding of, and decoding to, both RGB and Y′CbCr pixel formats
Apple ProRes 422 (HQ): This codec preserves visual quality at the same high level as Apple ProRes 4444, but for 4:2:2 image sources. With widespread adoption across the video post-production industry, Apple ProRes 422 (HQ) offers visually lossless preservation of the highest-quality professional HD video that a (single-link) HD-SDI signal can carry. This codec supports full-width, 4:2:2 video sources at 10-bit pixel depths, while remaining visually lossless through many generations of decoding and reencoding. The target data rate of Apple ProRes 422 (HQ) is approximately 220 Mbps at 1920 x 1080 and 29.97 fps.
Apple ProRes 422: This codec offers nearly all the benefits of Apple ProRes 422 (HQ), but at 66 percent of the data rate for even better multistream, real-time editing performance.
Apple ProRes 422 (LT): With a target data rate that is roughly 70 percent of the data rate of Apple ProRes 422 and 30 percent smaller file sizes than Apple ProRes 422, this codec is perfect for environments where storage capacity and bandwidth are at a premium.
Apple ProRes 422 (Proxy): This codec is intended for use in offline workflows that require low data rates but full-resolution video. The target data rate is roughly 30 percent of the data rate of Apple ProRes 422.