Q&A: Visual Basic 6

What is module?
variables and functions that are used throughout your program and on different forms can be stored in modules so that not to rewrite again each time the variables and functions when you need them in a form.

What is namespace?
A namespace is a collection of different classes. All VB applications are developed using classes from the .NET System namespace. The namespace with all the built-in VB functionality is the System namespace. All other namespaces are based on this System namespace. Namespaces organize the objects defined in an assembly. Assemblies can contain multiple namespaces, which can in turn contain other namespaces. Namespaces prevent ambiguity and simplify references when using large groups of objects such as class libraries.For example, the .NET Framework defines the ListBox class in the System.Windows.Forms namespace.

What is Lambda Expression?
A lambda expression is a function or subroutine without a name that can be used wherever a delegate is valid. Lambda expressions can be functions or subroutines and can be single-line or multi-line. You can pass values from the current scope to a lambda expression.

What is delegate?
A delegate is a form of object-oriented function pointer that allows a function to be invoked indirectly by way of a reference to the function. Delegates can be used to hook up event handlers and pass a procedure from one procedure to another. Delegates are objects that refer to methods. They are sometimes described as type-safe function pointers because they are similar to function pointers used in other programming languages. But unlike function pointers, Visual Basic delegates are a reference type based on the class System.Delegate. Delegates can reference both shared methods — methods that can be called without a specific instance of a class — and instance methods.

What is interface?
Interfaces define the properties, methods, and events that classes can implement. Interfaces allow you to define features as small groups of closely related properties, methods, and events; this reduces compatibility problems because you can develop enhanced implementations for your interfaces without jeopardizing existing code. You can add new features at any time by developing additional interfaces and implementations. There are several other reasons why you might want to use interfaces instead of class inheritance:
* Interfaces are better suited to situations in which your applications require many possibly unrelated object types to provide certain functionality.
* Interfaces are more flexible than base classes because you can define a single implementation that can implement multiple interfaces.
* Interfaces are better in situations in which you do not have to inherit implementation from a base class.
* Interfaces are useful when you cannot use class inheritance. For example, structures cannot inherit from classes, but they can implement interfaces.

What is assembly?
An assembly is the building block of a .NET application. It is a self describing collection of code, resources, and metadata (data about data, example, name, size, version of a file is metadata about that file). An Assembly is a complied and versioned collection of code and metadata that forms an atomic functional unit. Assemblies take the form of a dynamic link library (.dll) file or executable program file (.exe) but they differ as they contain the information found in a type library and the information about everything else needed to use an application or component. All .NET programs are constructed from these Assemblies. Assemblies are made of two parts: manifest, contains information about what is contained within the assembly and modules, internal files of IL code which are ready to run. When programming, we don't directly deal with assemblies as the CLR and the .NET framework takes care of that behind the scenes. The assembly file is visible in the Solution Explorer window of the project.