Histograms

I don’t know what Histograms are and at this point am too afraid to ask.

Well what are they ?

Let's start with a dataset of some things, importantly said data should have some differences, else well there's nothing to compare.
So the preliminary answer is that a histogram should give us some insights into those differences and even tell us if there are differences at all...

Data

Let’s say you are sitting at a coffee shop like the one I am at right now and you can see outside into a busy pedestrian street, to keep things simple let’s count the shirt color of the first 100 folks that wander by…

And here are the 100 shirts in the order they were observed :

At a glance we can "sort of" conclude that black shirts are popular followed by blue and white ones while orange and yellow shirts are not that common… We can do better than "sort of" by counting each color and thus…