Eager loading is a technique used in programming, particularly in the context of databases and object-relational mapping (ORM). It allows developers to load related data alongside the main data in a single query. For example, when retrieving a list of users, eager loading can fetch their associated posts at the same time, reducing the number of database calls and improving performance. This approach contrasts with lazy loading, where related data is fetched only when explicitly requested. By using eager loading, developers can minimize delays and ensure that all necessary information is available upfront, leading to a smoother user experience in applications.