It looks like you're asking about in the context of lifestyle and entertainment .

: Remind your audience to support creators by using official streaming services when possible, as many ultra-small encodes are unofficial distributions.

The breakthrough technology for the 300MB format. High-Efficiency Video Coding (HEVC) offers up to 50% better data compression than H.264 at the same level of video quality. This allows encoders to shrink a high-definition 720p or even a tightly optimized 1080p video into a 300MB file while maintaining surprising visual clarity.