One-Hot Encoding

First learned about this term through Machine Learning, but surprisingly I hear is as well in Digital Circuits.

Machine Learning

Where there is categorical data, we use one-hot encoding to convert it into features, where each category is a feature of 1.

 
We also need to remove one column because that is simply a duplicate because it is a [[Dummy Variable]] (i.e. redundant information).
 
It seems that [[Andrej Karpathy]] didn't worry about this however.