Difference between function and method

Functions

1. Functions have independent existence means they can be defined outside of the class. Ex:- main() function in C, C++ Language
2. Functions are defined in structured languages like Pascal,C and object based language like javaScript
3. Functions are called independently.
4. Functions are self describing unit of code.

 //function main in C
void main()
{
 int a,b,c;
 a=5;
 b=6;
 c=a+b;
 printf("Sum is : %d",c);
} 

Methods

1. Methods do not have independent existence they are always defined with in class. Ex:- main() method in C# Language that is defined with in a class
2. Methods are defined in object oriented languages like C#, Java
3. Methods are called using instance or object.
4. Methods are used to manipuate instance variable of a class.

 //method sum in C#
class demo
{
int a,b,c;
public void sum()
{
 a=5;
 b=6;
 c=a+b;
 Console.WriteLine("Sum is : {0}",c);
 }
}