The wiki pages aren't helping at all. What is a step function and how does it work? I've seen them used in the floor, ceil, frac and even signum functions. And although it is easy to understand what those functions do, their graphs are alien-looking thanks to the step functions. A brief explanation of how they're used in these cases might also be of help.
Edit: I apologize if I was a bit vague in my question.
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What exactly are these lines called, how do they work and how are they related to intervals?
Thank you in advance.