Function Overloading vs Function Overriding in C++

Function Overloading (achieved at compile time)

Function Overloading provides multiple definitions of the function by changing signature i.e. changing number of parameters, change datatype of parameters, return type doesn’t play any role. 

• It can be done in base as well as derived class
  .Example:  

void area(int a);
void area(int a, int b); 

Integer number: 5
Float number: 5.5
Integer number: 5 and float number:5.5

Function Overriding (achieved at run time)

It is the redefinition of base class function in its derived class with same signature i.e. return type and parameters. 

• It can only be done in derived class.
• Example:

Class a
{
public: 
 virtual void display(){ cout << "hello"; }
};

Class b:public a
{
public: 
 void display(){ cout << "bye";}
};