Differences between image(), createImage and createImg()

I am curious about these three image functions

  • image();
  • createImg();
  • createImage();

I have read the reference pages but still want some clear explanation.
Is the creatImage() works with pixel related graphic and the createImg() is for something like Gif image?!?

I also compared two examples from P5.js editor online and found that image(); in the older version of p5.js did not work with gif animation but the newer does today.

Are there anything else that distinct these 3 image functions?

Thanks in advance!