Information retrieval (IR) concerns about the organization, understanding, and access of information. Example applications of IR such as search engines (e.g., Google) and recommender systems (e.g., Spotify) have already become a significant part of everybody's lives. Thus, IR is considered to one of the most influential and commercially successful research topics in Artificial Intelligence. In this course, students will learn about the basic concepts of information retrieval and the underlying technologies that support the construction of modern IR systems. They will obtain hands-on experience on these techniques by proposing and finishing their own information retrieval projects using existing toolkits and the state-of-the-art algorithms.