A data structure is a way of organizing and storing data in a computer so that it can be accessed and modified efficiently. Common types of data structures include arrays, linked lists, stacks, and queues. Each type has its own advantages and is suited for different tasks, depending on how data needs to be processed. Data structures are essential in computer science because they enable efficient data management and retrieval. For example, a binary tree allows for quick searching and sorting of data, while a hash table provides fast access to data through key-value pairs. Understanding data structures is crucial for developing effective algorithms and software applications.