Data
Data is a collection of numbers, alphabets and symbols combined to represent information. A computer accepts the raw data as input and after processing of data, it produces improved data as output.

Atomic data:
Atomic data are the nondecomposable entity. For example, an integer value 111 or a character value "J" cannot be further divided.

Composite data:
It is a composition of several atomic data and it can be further divided into atomic data. For example, the Date of birth (05/07/1995) can be separated into three atomic values. The first one gives the day of the month, the second one gives the month and the last one is the year.
Data Types
A data type is a set of values and a set of operations defined on those values.
Example: int age; [age can hold, integer type of data]
Every programming language has a method for declaring a set of variables of a particular type.
Abstract Data Types (ADT)
ADT in programming language means a userdefined extension to the native data types available in the programming language.
It consists of:
 A set of values
 A set of operations
In ADT, the implementation details remain hidden from the user. ADT is widely referred to as objectbased programming.
Data Structure
The data structure indicates the following things:
 Organization of data
 Associativity among data elements
 Accessing methods
 Operations on data
 Processing alternatives for data
The data structure deals with the representation of data considering not only the elements stored but also their relationship with each other.
A wellsuited data structure must be chosen so that the relationship between data elements can be expressed. A data structure is an instance of an ADT.
Types of Data Structures

Primitive data structures:
The primitive data structures are primitive data types. The int, char, float, double, and pointer are the primitive data structures that can hold a single value.

Nonprimitive data structures:
The nonprimitive data structure is divided into two types:

Linear:
Elements are arranged sequentially is known as Linear data structure. A onetoone relationship can be handled by the linear data structure. Arrays, Linked lists, Stacks, and Queues are examples of Linear data structures.

Nonlinear:
All onetomany, manytoone, and manytomany relationships are handled by Nonlinear data structures. Trees, graphs, and tables are examples of Nonlinear data structures.

Linear:
Operations on Data Structures
The common operations are performed on data structures are:

Traversing:
A data structure is accessing each element and accessing only once.

Searching:
Finding the location of elements within the given data structure.

Insertion:
Adding the new element in a data structure.

Update:
Update the element, i.e. replace the element with another element.

Deletion:
Removing the element from the data structure.

Sorting:
Arranging the elements of a data structure either in an ascending or descending order.