Keras: The model building API of TensorFlow
Keras was developed as a separate library that provides high-level building blocks to build models conveniently. It was initially platform-agnostic and supported many softwares (for example, TensorFlow and Theano).
However, TensorFlow acquired Keras and now is an integral part of TensorFlow for building models effortlessly.
Keras’s primary focus is model building. For that, Keras provides several different APIs with varying degrees of flexibility and complexity. Choosing the right API for the job will require sound knowledge of the limitations of each API as well as experience. The APIs provided by Keras are: