First of all, you should understand the difference between vector map and bitmap (you can look for it) and the basic format of video. Generally speaking, vector pictures with the same pixel are smaller than bitmaps. Flash's main strength is vector picture processing and making vector picture animation, while ordinary video editing software processes files in AVI and other formats, and their encoding methods are different from those of SWF exported by Flash.

Secondly, in the details, especially the tween animation, we can see that the contents in the middle normal frame are basically automatically added by the computer, and it can also be simply understood that the SWf format file can be encoded as long as the information on the key frame and the tween information in the middle are stored. For key frame animation, most cartoons use frame-by-frame animation, in which each frame is a vector diagram, so it is also very small.

Thirdly, the swf files to be published on the network generally support 255 colors, which means that the information in the video you usually see is full color, and they have more information, and this feature of SWF files makes it look slim.

Finally, you'd better find another explanation! There is no end to learning!