The Estimator is a high-level TensorFlow API that makes developing deep learning models much more manageable since you can use them to write models with high-level intuitive code. It builds a computation graph and provides an environment where we can initialize variables, load data, handle exceptions, and create checkpoints.

The tfestimators package is an R interface for the TensorFlow Estimator API. It implements various components of the TensorFlow Estimator API in R, as well as many pre-built canned models, such as linear models and deep neural networks (DNN classifiers and regressors). These are called pre-made estimators. The Estimator API does not have a direct implementation of recurrent neural networks or convolutional neural networks but supports a flexible framework for defining arbitrary new model types. This is known as the custom estimators framework.