What is information retrieval and what tasks does it solve?

Information retrieval (IR) is a field related to searching and extracting relevant information from large volumes of unstructured data, such as text documents, web pages, images, etc.

Main tasks of IR:

• Indexing data for quick search
• Finding documents or objects relevant to the user's query
• Ranking results by relevance
• Natural language processing to improve query understanding

Example: a search engine that finds relevant articles or websites based on keywords. In machine learning, IR is often used for training ranking models (Learning to Rank) that optimize the order of results.