AI glossary

What is activation function?

Short answer

A function applied to a neuron's weighted sum (e.g. ReLU, sigmoid) that adds non-linearity, letting stacked layers learn complex patterns.

For example

ReLU simply turns negative numbers into zero and keeps positive ones. That small bend is what lets a stack of layers draw curved boundaries instead of only straight lines.

Learn it in a free lesson

Questions

What is activation function in simple terms?

A function applied to a neuron's weighted sum (e.g. ReLU, sigmoid) that adds non-linearity, letting stacked layers learn complex patterns.

What is an example of activation function?

ReLU simply turns negative numbers into zero and keeps positive ones. That small bend is what lets a stack of layers draw curved boundaries instead of only straight lines.

Where can I learn about activation function for free?

AI in Bed explains it in the free lesson "Neural networks, gently" (Beginner level, 6 minutes), with no sign-up.