Python Terms Question

[SamanthaM]

Learning ArcPy, just trying to familiarize myself with the terms. In the below image I believe I have identified everything correctly, except what "lyr" represents.

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The icon ArcGIS displays is a purple note stack. I am not sure what the term for this is. For example the term "For" is a statement, I believe, so what is the term for Lyr?

Here is another example
[ATTACH=CONFIG]14976[/ATTACH]

[FabianBlau]

It is often helpful to print variables before/after function calls.
Its an easy way to find errors.