What is the difference between Loss, accuracy, validation loss, Validation accuracy?

Question

At the end of each epoch, I am getting for example the following output:

Epoch 1/25
2018-08-06 14:54:12.555511: 
2/2 [==============================] - 86s 43s/s         


        

Answer 1

In your model.compile function you have defined a loss function and a metrics function.

Your "loss" is the value of your loss function (unknown as you do not show your code) Your "acc" is the value of your metrics (in this case accuracy) The val_* simply means that the value corresponds to your validation data.

Only the loss function is used to update your model's parameters, the accuracy is only used for you to see how well your model is doing.

You should seek to minimize your loss and maximize your accuracy. Ideally the difference between your validation data results and your training data results should be similar (allthough some difference are expected)