A data structure is a specialized form of organizing the data.
Data structures can implement one or more particular abstract data type (ADT)
A data structure is a concrete implementation of the specification provided by an ADT.
Examples:
Array: elements of arrays are referenced via an index number.
Linked data structure: are based on storing addresses of subsequent data items within a given item itself.
Association arrays: Implementation of Map/Associative Array/Dictionary which maintains key-value pairs using linked data structure.
Hash table or hash map: like Association Array but uses a hash function to compute an index into an array of buckets or slots, from which the desired value can be found.
Record: a collection of fields possibly of different data types.
Class: contains data fields, like a record, as well as various methods which operate on the contents of the record.