Here’s a quick 101 on what the settings options for video on your phone mean.
720p, 1080p, 4k. These numbers represent the number of pixels in the image. They are shortened to the number of pixels across the height of the screen. The full descriptions are 1920 x 1080p, 1280 x 720p, 3840 x 2160 (this is referred to as 4K as the width pixels are approximately 4,000).
You will also hear these numbers described as SD – Standard HD, HD – High Definition or Ultra HD. These are standards set by TV broadcasting and describe the capability of TV to accept and display different formats. For example, if you an HD TV it can display 1920 x 1080p format as footage filmed in 1080p was intended to be viewed.
Now which one to choose in your phone? Generally speaking, unless your subject matter needs very high levels of crispness or will be shown at large scale, HD works for most purposes. It’s great for web footage, social media videos and will be compressed to a smaller file size on YouTube, Facebook, Instagram etc.