A data structure is a specialized way of organizing, storing, and managing data in a computer so that it can be used efficiently. It defines the relationship between the data and the operations that can be performed on it. Common data structures include arrays, linked lists, stacks, queues, trees, graphs, and hash tables. Each type has its own strengths and is suitable for specific kinds of tasks or problems. Choosing the right data structure is essential for optimizing performance in terms of speed and memory usage. Data structures form the foundation of efficient algorithms and play a critical role in software development, system design, and problem-solving in computer science.