Topic modeling is a powerful technique used in natural language processing to identify topics in a text corpus automatically. Latent Dirichlet Allocation (LDA) is one of the most popular topic modeling techniques, and in this tutorial, we'll explore how to implement it using the Gensim library in Python.

Sentence similarity involves determining how closely related two sentences are in meaning. It measures the similarity between two or more sentences using a similarity score. We often want to measure text similarity in various NLP tasks. Some of those tasks include information retrieval, text summarization, and question answering. One way of achieving that is by using a BERT Transformer model.