 Data structure is a fundamental concept of any programming language, essential for algorithmic design.
 It is used for the efficient organization and modification of data.
 DS is how data and the relationship amongst different data is represented, that aids in how efficiently various functions or operations or algorithms can be applied.
Types
There are two types of data structures:

Linear data structure: If the elements of a data structure result in a sequence or a linear list then it is called a linear data structure. Example: Arrays, Linked List, Stacks, Queues etc.

Nonlinear data structure: If the elements of data structure results in a way that traversal of nodes is not done in a sequential manner, then it is a non linear data structure. Example: Trees, Graphs etc.
Applications
Data structures form the core foundation of software programming as any efficient algorithm to a given problem is dependent on how effectively a data is structured.
 Identifiers look ups in compiler implementations are built using hash tables.
 The Btrees data structures are suitable for the databases implementation.
 Some of the most important areas where data structures are used are as follows:
 Artificial intelligence
 Compiler design
 Machine learning
 Database design and management
 Blockchain
 Numerical and Statistical analysis
 Operating system development
 Image & Speech Processing
 Cryptography