In C++, special member functions called constructors and destructors are used for initializing and ruining objects, respectively. They are fundamental to class design and object-oriented programming. Let's move longer into constructors and destructors:

Constructors:

1. Purpose: Constructors are used to initialize an object's attributes or data members when it is created. They make sure an object starts off in an appropriate condition.
2. Name: Constructors are defined as public member functions and share the same name as the class.
3. Overloading: Constructor overloading, which is a feature of C++, enables you to define multiple constructors for a class. Different parameter lists for each constructor allow for the creation of objects with various initializations.
4. Default Constructor: C++ provides a default constructor with no arguments if you do not define any constructors for your class. It sets the default values for member variables (such as 0 for numeric types and the empty string for string types).

A class that has multiple constructors can be seen in the following example:

class MClass {
public:
    int Data;

    MClass() {
        Data = 0;      // Default Constructor
    }

    MClass(int Value) {
        Data= Value;                         // Parameterized Constructor
    }
};

Destructors:

1. Purpose: Destructors are used to clean up resources and perform necessary cleanup tasks when an object is destroyed (e.g., when it exits scope or when 'delete' is called on a dynamically allocated object).
2. Name: Destructors are identified by the class name followed by a tilde ('~'). In addition, they are described as public member functions.
3. No Overloading: You cannot define more than one destructor for a class, in contrast to constructors. There is only one destructor per class.
4. Implicitly Generated Destructor: If you don't specify a destructor for your class, C++ automatically generates one for you; it serves no special purpose. For classes that don't control resources like dynamic memory or file handles, it usually suffices.

Here is a class with a destructor example:

class ResourceHolders {
public:
    int* resources;

    ResourceHolders() {     // Constructor
        resources = new int[100];             // Initialize and allocate resources
    }

    ~ResourceHolders() {        // Destructor
        delete[] resources;              // Clean up and release resources
    }
};