**What Is Data Structure? How Many Types?**

Data structure is a way of organizing and storing data so that it can be accessed and manipulated efficiently. It provides a systematic way of managing and organizing large amounts of data, making it easier to perform operations such as searching, sorting, and inserting data.

## Types of Data Structures

There are various types of data structures, each designed to handle different types of data and perform specific operations efficiently. Let’s explore some commonly used data structures:

### 1. Arrays

An array is a collection of elements stored in contiguous memory locations.

Elements in an array can be accessed using their index value. Arrays are widely used due to their simplicity and efficient access time.

### 2. Linked Lists

A linked list is a collection of nodes, where each node contains both the data and a reference (or link) to the next node in the sequence. Linked lists provide dynamic memory allocation, which allows for efficient insertion and deletion operations.

### 3. Stacks

A stack is a linear data structure that follows the Last-In-First-Out (LIFO) principle.

It allows insertion and deletion of elements only at one end called the top. Stacks are commonly used in programming languages for managing function calls, recursion, and expression evaluation.

### 4. Queues

A queue is also a linear data structure that follows the First-In-First-Out (FIFO) principle.

Elements are inserted at one end called the rear, and deleted from the other end called the front. Queues are widely used in operating systems for process scheduling, handling requests, and implementing algorithms like breadth-first search.

### 5. Trees

Trees are hierarchical data structures that consist of nodes connected by edges.

Each node can have zero or more child nodes. Trees are used for representing hierarchical relationships, organizing data, and implementing efficient searching and sorting algorithms.

### 6. Graphs

A graph is a collection of nodes (or vertices) connected by edges.

Graphs are used to represent complex relationships between objects and can be either directed or undirected. They are commonly used in social networks, routing algorithms, and optimization problems.

### 7. Hash Tables

A hash table (or hash map) is a data structure that uses a hash function to map keys to values.

It provides constant-time average-case complexity for search, insert, and delete operations. Hash tables are widely used in databases, caches, and in implementing various algorithms.

## Conclusion

Data structures play a crucial role in computer science and programming. Understanding different types of data structures allows us to choose the most appropriate one for solving specific problems efficiently. Whether it’s an array for simple storage or a complex graph for modeling intricate relationships, data structures provide the foundation for efficient data management and manipulation.