Resolution Guide:4k: The highest-quality, premium video size at 4x the pixels of standard HD resolutions. Get the sharpest possible image and best color depth by integrating 4k footage into your creative work. For further editing control, look for the â€œR3Dâ€ file type, if available. 4k clips are usually recommended for high-end commercial use, within the limits of the itemâ€™s releases and royalty-free license. HD (High Definition or Hi-Def): The hi-res industry standard in 1080 & 720 sizes. HD is the best size for modern TVs, general video streaming (YouTube, Vimeo, etc.), and is also generally applied in commercial & editorial uses within stated legal limits. SD (Standard Definition): Standard def is the traditional size of TVs up until the mid-2000s. Currently, SD is the minimum quality needed to digitally stream content, and usually less expensive than HD or 4K. SD is also ideal for personal creative projects.