<p>I think it is by analogy with an electrical rectifier. A rectifier allows current to flow in one direction but blocks current in the other direction. Or if you prefer it allows voltage in one polarity but won't allow a voltage in the opposite polarity. Which is also what a ReLU does.</p>

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2022-06-28T12:03:05.260Z
2022-06-28T12:03:05.260Z
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<p>ReLU stands for Rectified Linear Unit. Linear Unit, I understand, since the function is piecewise linear. But what does rectified mean?</p>
<p>I looked up the definition and it said:</p>
<blockquote>
<p>denoting an electric current that has been converted from alternating current to direct current</p>
</blockquote>
<p>But I don't quite see how this can connect to ReLU function. While it does have a bend at <span class="math-container">$x = 0$</span> indicating a change in direction, not sure how I can work this into the idea of current directions.</p>

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2022-06-28T08:10:30.770Z
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.
Chillston
<deep-learning><terminology><activation-functions><relu>
Where does the "rectified" in ReLU come from?
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# Where does the "rectified" in ReLU come from?

(Asked by: username_0 on 2022-06-28)

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.

**Tags:** deep-learning, terminology, activation-functions, relu

> **Comments:**
> **username_1**: 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.  

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## 1 answers

### Answer by username_2 on 2022-06-28. Score: 1 | Accepted answer

I think it is by analogy with an electrical rectifier. A rectifier allows current to flow in one direction but blocks current in the other direction. Or if you prefer it allows voltage in one polarity but won't allow a voltage in the opposite polarity. Which is also what a ReLU does.


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