In this project, a sample input text file consisting of Doc IDs and sentences is given. Based on this provided input text file, the task is to build an inverted index using the information extracted from the given data. The index is stored as a Linked List in memory, as the examples shown in 'An Introduction to Information Retrieval', by Christopher D. Manning, Prabhakar Raghavan, Hinrich Schütze - (Chapter 1 – Boolean Retrieval). Having built this index, a Document-at-a-time (DAAT) strategy is implemented to return Boolean query results. Finally, the TF-IDF score is calculated to rank and sort the query results.