Deep learning techniques make use of neural network-based models and have seen increasing interest in the last few years.A Google trends website for the search term deep learning provides the following plot:

The preceding plot has 100 as the peak popularity of a search term, and other numbers are relative to this highest point. It can be observed that the interest in the term deep learning has gradually increased in popularity since around 2014. For the last two years, it has enjoyed peak popularity. One of the reasons for the popularity of deep learning networks is the availability of the free and open source libraries, TensorFlow and Keras.