NLTK(Natural Language Toolkit) is the most popular and widely used python library for doing Natural Language Processing(NLP) or Text Mining.
Bias is the difference between actual value and the predicted value that a model predicts. In machine learning, data is fed to the machine learning model, the model finds the patterns from data and learns from data.
Imbalance dataset is such a type of dataset that has an unequal distribution of data among the classes of classification of datasets. Most machine learning algorithms work well with balanced datasets.
K-Nearest Neighbor(KNN) algorithm is a supervised machine learning algorithm that is used for classification and regression analysis.