What is a dynamic RNN in TensorFlow?

Question

I am confused about what dynamic RNN (i.e. dynamic_rnn) is. It returns an output and a state in TensorFlow. What are these state a

Answer 1

While AlexDelPiero's answer was what I was googling for, the original question was different. You can take a look at this detailed description about LSTMs and intuition behind them. LSTM is the most common example of an RNN.

http://colah.github.io/posts/2015-08-Understanding-LSTMs/

The short answer is: the state is an internal detail that is passed from one timestep to another. The output is a tensor of outputs on each timestep. You usually need to pass all outputs to the next RNN layer or the last output for the last RNN layer. To get the last output you can use output[:,-1,:]