What's the difference between standard definition and fluency? Which one is better?

Options that appear when watching a video;

Usually there are four kinds of videos on the network: smooth, standard definition, high definition and ultra-clear.

High-definition ultra-clear needs no explanation. At first glance, you can see that the file is large, with long buffering time and high definition. SD appeared after we uploaded the video and automatically decompressed it from the video website.

So you will find that the uploaded video is not as clear as what you see on the computer, which is the reason, but it is still clearer than the smooth version.

Smoothness means that the video is relatively compressed and the details are blurred. It is rare to see the difference when watching movies, but when watching modern high-definition movies, you can see the details, just like playing games and turning off some special effects loading, which is much smoother. Because the relative compression is smaller and the buffer is faster.