A class defines the data and behavior of a type by grouping together variables, methods, and events. It supports encapsulation by allowing fields and methods to be declared as instance or static members. A class is declared using the class keyword followed by the class name and body surrounded by curly braces. Objects are instances of a class that can access members using the dot operator. Constructors are special methods that initialize an object when created with the new operator.

2.  https://www.slideshare.net/adeel02

3.  A class is a construct that enables you to create your
own custom types by grouping together variables of
other types, methods and events.
 It defines the data and behavior of a type.
 Supports the OOP principle "encapsulation“
 Fields and methods can be::
Instance (or object members)
Static (or class members)

4. Class definition consists of
 Class declaration
 Data Fields
 Constructors
 Properties
 Methods
class test{
public int a = 5, b = 10;
public void mul(){
Console.Write("The Result of
Multiply is = {0}", a * b);
Console.ReadLine();
}}

5. Classes
Classes are declared by using the keyword class
followed by the class name and a set of class
members surrounded by curly braces { }.
class House
{
Body
...
}

6. Basic syntax for class declaration
Class comprises a class header and class body.
class class_name
{
class body
}
Note: No semicolon (;) to terminate class block.
But statements must be terminated with a semicolon ;

7.  In C#, individual classes and class members need
to be prefixed with visibility modifiers.
 By default, if you declare a member variable (or
anything else) in a class but do not specify its
access level, the member is considered private
and cannot be accessed from outside, i.e. by a
non-member of that class.
 Therefore, to make a member accessible by other
classes, you must declare it as public.

8.  Object is an abstraction of real world entity.
 Syntax for declaring objects is as follows :
 MyClass objMyClass = new MyClass();

9.  It can have its own copy of data members.
 It can be passed to a function like normal variables.
 The members of the class can accessed by the object
using the object to member access operator or dot
operator(.).

10.  Create Object
 Call function and variables with the help of object
 MyClass objMyClass = new MyClass();
 objMycClass.function_name();
 objMycClass.variable;

11. Constructors
public MyClass(parameters) {...}
• new operator – create an instance of the class
MyClass objMyClass = new MyClass();
public Person()
{
name = null;
age = 0;
}

12.  class testt{
 public static int a = 5, b = 10;
 public static void mul(){
 Console.Write("The Result of Multiply is = {0}", a
* b);
 Console.ReadLine();
 }}

13.  MyClass objMyClass1 = new MyClass();
 objMycClass1.function_name();
 MyClass objMyClass2 = new MyClass();
 objMycClass2.function_name();
 MyClass.function_name();