Data structure Data structures is the specialized format to organize and manipulate data. A data structure dictate way data is acquire, and form in your computer. The goal is to use and access data on efficient manner. There are type of data structure for example array, tree, hash, and graph. Different kind of application use specific data structure to achieve efficient operation. The complexity and the use of data structure describe on big O notation where O(1) indicate a fast algorithm that will always execute in the same linear time.