# Where does the "rectified" in ReLU come from?

ReLU stands for Rectified Linear Unit. Linear Unit, I understand, since the function is piecewise linear. But what does rectified mean?

I looked up the definition and it said:

denoting an electric current that has been converted from alternating current to direct current

But I don't quite see how this can connect to ReLU function. While it does have a bend at $$x = 0$$ indicating a change in direction, not sure how I can work this into the idea of current directions.

• I always linked it to engineering, a rectifier converts alternating current into direct current. As ReLU gets rid of the negative side of the linear function I think its fitting. Not sure though if thats also what the authors had in mind. Jun 28 at 8:10