Danfo.js is a Javascript package inspired by the Pandas library. It provides high-performance data structures such as Series, DataFrame, etc. to facilitate the manipulation of columnar or relational data and functionality that enables users to query, aggregate, transform, and join datasets, among other operations. It is built on top of Tensorflow.js, so Danfo.js data structures can be converted directly into Tensors. Similar to sklearn, Danfo.js also provides built-in, standard data preprocessing functions such as scalers and encoders.