TensorFlow is a powerful open-source software library for numerical computation and machine learning. It provides libraries and tools for developers to create and deploy machine learning models that can be used to solve a variety of tasks, such as predicting outcomes, recognizing patterns, and understanding natural language. TensorFlow also allows developers to use JavaScript to build and run machine learning models with the help of its JavaScript API. This makes it easier for developers to develop and deploy machine learning models in JavaScript applications.