# Help on how to read 2-categories diagrams

I've seen 2-categories diagrams, where there are 2-cells and 1-cells morphisms, but I do not understand how to read them.

Apparently it seems to be some kind of rule that says that you have to follow the paths (as in a horizontal composition) and then vertically compose all of them? Is there any place when I can read how to read them?

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I think that the double-categorical approach which represents 2-cells $\alpha$ as squares like $$\begin{array}{ccc} x &\xrightarrow{f}& y \\ \downarrow&\alpha &\downarrow\\ z &\xrightarrow[g]{}& w \end{array}$$ is better suited than the "globular" approach: as an example, I find horizontal composition far more intuitive from the visual point of view.