What is Overloading? What is Overloads? What is Overload?

Overloading - is the concept of using one function or class in different ways by changing the signature of its parameters. We can define a function with multiple signatures without using the keyword Overloads, but if you use the Overloads keyword in one, you must use it in all of the function's Overloaded signatures.

The Overloads keyword is used in VB.NET, while the Overload keyword is used in C# (There is no other difference). The Overloads property allows a function to be described using deferent combinations of parameters. Each combination is considered a signature, thereby uniquely defining an instance of the method being defined.

Overloading is a way through which polymorphism is achieved.

What is an access modifier? What are the different types of Access modifiers?

Access Modifiers - Keywords used to change the way members of a class are accessed. The main purpose of using access specifiers is to provide security to the applications. The availability (scope) of the member objects of a class may be controlled using access specifiers.

What is a property? What is an event?

Property - A property is a thing that describes the features of an object. A property is a piece of data contained within a class that has an exposed interface for reading/writing. Looking at this definition, we might think we could declare a public variable in a class and call it a property. While this assumption is somewhat valid, the real technical term for a public variable in a class is a field. The main difference between a field and a property is in the inclusion of an interface.

We make use of Get and Set keywords while working with properties. We prefix the variables used within this code block with an underscore. Value is a keyword, that holds the value which is being retrieved or set.ss="a">

Private _Color As String
   Public Property Color()
    Get
      Return _Color
    End Get
    Set(ByVal Value)
      _Color = Value
    End Set
End Property

Event - An action that an object does. When something happens, we say an event has happened. For example, when a button is clicked, we say it is the click( ) event. When a mouse hovers on an image, we say the mouseover( ) event has taken place.

What is polymorphism?

Polymorphism means allowing a single definition to be used with different types of data (specifically, different classes of objects). For example, a polymorphic function definition can replace several type-specific ones, and a single polymorphic operator can act in expressions of various types. Many programming languages implement some forms of polymorphism.

The concept of polymorphism applies to data types in addition to functions. A function that can evaluate to and be applied to values of different types is known as a polymorphic function. A data type that contains elements of different types is known as a polymorphic data type.

Polymorphism may be achieved by overloading a function, overloading an operator, changing the order of types, changing the types using the same name for the member in context.

Example:
Public Class Calc
{
public void fnMultiply(int x, int y)
{ return x * y; }
public void fnMultiply(int x, int y, int z)
{ return x * y * z; }
}
...
... Calc obj;
int Result;
Result = obj.fnMultiply(2,3,4); // The second fnMultiply would be called
Result = obj.fnMultiply(3,4); // The first fnMultiply would be called

Inheritance (object-oriented programming)

In object-oriented programming (OOP), inheritance is a way to reuse code of existing objects, establish a subtype from an existing object, or both, depending upon programming language support. In classical inheritance where objects are defined by classes, classes can inherit attributes and behavior (i.e., previously coded algorithms associated with a class) from pre-existing classes called base classes or superclasses or parent classes or ancestor classes. The new classes are known as derived classes or subclasses or child classes. The relationships of classes through inheritance gives rise to a hierarchy. In prototype-based programming, objects can be defined directly from other objects without the need to define any classes, in which case this feature is called differential inheritance.
Complex inheritance, or inheritance used within an insufficiently mature design, may lead to the yo-yo problem.
The inheritance concept was invented in 1968 for Simula.^[1]

Subclasses and superclasses

A superclass, base class, or parent class is a class from which other classes have been derived. The classes that are derived from a superclass are known as subclasses, or derived classes, or child classes.
A superclass allows for a generic interface to include specialized functionality through the use of virtual functions.
The superclass mechanism is extensively used in object-oriented programming because of the reusability that can be achieved: common features are encapsulated in modular objects. Subclasses that wish to implement special behavior can do so via virtual methods, without having to reimplement the superclass's behavior.
A subclass is a class that inherits some properties from its superclass.
Subclasses and superclasses are often referred to as derived and base classes, respectively,

Applications

Inheritance is used to co-relate two or more classes to each other. With the use of inheritance we can use the methods and the instance variables of other classes in any other classes.

What is inheritance?

Inheritance - is the concept of passing the traits of a class to another class.

A class comprises of a collection of types of encapsulated instance variables and types of methods, events, properties, possibly with implementation of those types together with a constructor function that can be used to create objects of the class. A class is a cohesive package that comprises of a particular kind of compile-time metadata. A Class describes the rules by which objects behave; these objects are referred to as "instances" of that class. (Reference)

Classes can inherit from another class. This is accomplished by putting a colon after the class name when declaring the class, and naming the class to inherit from—the base class—after the colon. (Reference) 

 Whats the difference between a class and an object?

In any object Oriented language, an object is the backbone of everything that we see. A class is a blueprint that describes how an instance of it (object) will behave. To create a class, we define it in a "Code File", with an extension *.cs or *.vb. We make use of the keyword class.

Example
Lets create a class named Laptop
public class Laptop
{
  private string sbrand;
  public Laptop() {}
  public Laptop(string name)
  {
    sbrand = name;
  }
}

From our code that references this class, we write...
Laptop lp = new Laptop("Lenovo"); //Passing a variable to the class constructor

Once the class object is created, the object may be used to invoke the member functions defined within the class. We may allocate any number of objects using the new keyword. The new keyword returns a reference to an object on the heap. This reference is not to the actual object itself. The variable being refered is stored on a stack for usage in the application. When we allocate an object to a heap, its managed by the .NET runtime. The garbage collector takes care of the object by removing it from the heap, when it is no longer reachable by any part of the code.

What is a class member? What is an object?

The entities like events, properties, fields and functions encapsulated within a class are called class members. A constructor of a class that resides within it is also a form of a class member.

When we instantiate a class in order to use its encapsulated class members, this instantiated class entity is called the object. Difference between class & object