Video encoding takes raw video image data and bundles it up into a format that can be viewed inside other applications. The video’s quality, file size, resolution, and many other factors are determined by the encoding process.
Most apps use ‘constant bitrate’ video encoding, which will use bitrates (eg. 5500kbps, 10mbps) to encode the video at an unchanging compression rate. However, when the video contains footage of lots of motion, the chosen bitrate can’t keep up and clips can become blurry -- especially true for many FPS games. A consistent bitrate is helpful when streaming video (like to Twitch), or trying to maintain a very consistent file size, but not as much when wanting to locally save high-quality clips.
Moments uses ‘constant rate factor’ encoding (CRF). When saving a clip with Moments, the video will be encoded to maintain the same quality no matter what’s happening inside the clip. Instead of being limited to hitting a specific bitrate, clips will look as good as they possibly can and only require the disk space and system resources as is absolutely needed.