In order to be a highly efficient, flexible, and production-ready library, TensorFlow uses dataflow graphs to represent computation in terms of the relationships between individual operations. Dataflow is a programming model widely used in parallel computing and, in a dataflow graph, the nodes represent units of computation while the edges represent the data consumed or produced by a computation unit.

As seen in the previous chapter, Chapter 2, Neural Networks and Deep Learning, representing computation using graphs comes with the advantage of being able to run the forward and backward passes required to train a parametric machine learning model via gradient descent, applying the chain rule to compute the gradient as a local process to every node; however, this is not the only advantage of using graphs.

Reducing the abstraction level and thinking about the implementation...