Kerning is modifying the spacing between individual characters. The final triumph of kerning (this is my opinion) is the ligature. See
Kerning on xkcdexplained for a bit more information to go with the cartoon below.
I do notice kerning but then I've been a bit of a typography geek for decades. What is that phrase?, Once you've seen it, you can't unsee it? Notice the spacing in the upper lines of the kerning for a walrus image compared to the bottom two line.