1. Softmax is a non-linear activation function generally used as the last layer of a classification model

the defination and formula of softmax is:

 

from the following example, we can see this network use softmax layer as the last layer to output 10 probability value

from keras import models
from keras import layers

network = models.Sequential() # sequential model
network.add(layers.Dense(512, activation='relu', input_shape=(28*28,)))
network.add(layers.Dense(10, activation='softmax'))