Comic books have their own structure, conventions, and language. In a seminal 1988 essay, two cartoonists broke down elements of this syntax using a single Nancy comic strip.

This essay is often used to teach the analysis of comics; the Wikipedia article suggests that a quarter of higher education courses on comics use this essay as a required reading.
For a more extended look at comic syntax, it’s also worth checking out the longer and more detailed Understanding Comics and Comics and Sequential Art.