Ggplot2 - quirks of plot types

ggplot2 has a bunch of different types of plots. Some of them seem straightforward, others don’t and yet others have properties that I at least wouldn’t expect.
I’ll start with a plot type that I’ve been thinking about recently: geom_dotplot(). For the most part it seems straight forward: adds dots to bins of number ranges for each data in that bin. The y axis you would think would be a count of how many dots there are, and within the plot that is true, you count the dots going up and it tells you how many entries are in that range. However the y axis seems to be labeled count with decimal numbers from 0 to 1. What is that for,how do I interpret that, how do I get it to be counts of the dots?
How is a dot plot different from a histogram? The only thing I can think of is that a dot plot is very discrete in the y direction, but MAYBE you could make a histogram that was more continuous in the y direction?

Linked is a resource I find helpful when dealing with ggplot2: https://nyu-cdsc.github.io/learningr/assets/data-visualization-2.1.pdf

Also, I’m looking at the documentation for dotplot, how do I get one dot to represent multiple data points?