Before answering what is data structure? First, we should see that computers do store, retrieve, and process a large amount of data. If this data is stored in well organized way on storage media and in computer's memory then it can be quickly made available for processing that further reduces the latency and the user is provided fast response. A data structure, in the simplest term is a scheme for organizing logically related data in computer's memory.

A data structure should be seen as a logical concept that must address two fundamental concerns. First, how the data will be stored and logical relationship among data elements, and second, what operations will be performed on it? As data structure is a scheme for data organization so the functional definition of a data structure should be independent of its implementation. The functional definition of a data structure is known as ADT (Abstract Data Type) which is independent of implementation. The implementation part is left on developers who decide which technology better suits to their project needs. For an example, a stack is a data structure which supports operations such as push and pop. A stack can be implemented in a number of ways, for example using an array or using a linked list.

Data structures are the building blocks of a program; rightly chosen data structure surely ascertains efficiency of the program. For example, for frequent read operations on a list; array will be the right data structure, while for frequent write operations linked list will be the right choice.