Data structures are ways to organize and store information in a computer so that it can be accessed and modified efficiently. They help programmers manage large amounts of data by providing a framework for organizing it. Common examples of data structures include arrays, linked lists, and trees, each serving different purposes depending on the needs of the application. Choosing the right data structure is crucial for optimizing performance. For instance, if you need to quickly search for an item, a hash table might be the best choice, while a stack is useful for managing tasks in a last-in, first-out manner. Understanding these structures can greatly enhance programming skills.