This document provides an introduction to information retrieval and recommender systems. It begins with defining information retrieval as finding documents that satisfy an information need from large collections. It then discusses how documents are indexed and preprocessed, including tokenization, stopwords removal, and lemmatization. Boolean and vector space retrieval models are introduced. The document also defines recommender systems as systems that suggest items of interest to users based on their preferences. It describes collaborative filtering and content-based recommender approaches.