What is the difference between a Class Library and a Namespace?

Class Library is another major entity of the .NET Framework (the other being the CLR). This library gives the program access to runtime environment. The class library consists of lots of prewritten code that all the applications created in .NET will use. The code for all the elements like forms, controls actually comes from the class library. The main class library in .NET is mscorlib.dll. This library contains a large number of core types that encapsulate a wide variety of common tasks. When a .NET application, there is automatic access to this library. We may view the class libraries provided by the .NET Framework by seeing the Global Assembly Cache (Go to C:\Windows\Assembly OR C:\Winnt\Assembly).

Namespace is a grouping of related types contained in an assembly. For example, the System.Drawing namespace consists of classes, methods that are grouped together to achieve similar tasks.
Note that a single assembly like mscorlib.dll may contain any number of namespaces. In fact, namespaces may be nested (means a namespace within a namespace) to arrange classes in a hierarchical fashion.

Also note that any language,that works on the .NET environment, targets the same set of namespaces & types provided by the .NET framework.

Explain Namespace.

Namespaces are logical groupings of names used within a program. There may be multiple namespaces in a single application code, grouped based on the identifiers’ use. The name of any given identifier must appear only once in its namespace.

Which namespace does a webpage belong? What is the base class of a webpage?

System.Web.UI.Page is the base class from which all web pages in ASP.NET derive from.

Which namespace is needed to implement debug and trace?

Debug and trace class belongs to System.Diagnostic namespace.

What is the difference between Namespace and Assembly?

Namespace:
1. It is a Collection of names wherein each name is Unique.
2. They form the logical boundary for a Group of classes.
3. Namespace must be specified in Project-Properties.

Assembly:
1. It is an Output Unit. It is a unit of Deployment & a unit of versioning. Assemblies contain MSIL code.
2. Assemblies are Self-Describing. [e.g. metadata,manifest]
3. An assembly is the primary building block of a .NET Framework application. It is a collection of functionality that is built, versioned, and deployed as a single implementation unit (as one or more files). All managed types and resources are marked either as accessible only within their implementation unit, or by code outside that unit.

Can I easily rename a solution or project?

Yes-right-click from the Solution Explorer and choose Rename.You’ll also have to edit the namespace declarations in any source code files you’ve created.

What is the difference between a namespace and an assembly name?

A namespace is a logical naming scheme for types in which a simple type name, such as MyType, is preceded with a dot-separated hierarchical name. Such a naming scheme is completely under the control of the developer. For example, types MyCompany.FileAccess. A and MyCompany.FileAccess.B might be logically expected to have functionality related to file access. The .NET Framework uses a hierarchical naming scheme for grouping types into logical categories of related functionality, such as the Microsoft ASP.NET application framework, or remoting functionality. Design tools can make use of namespaces to make it easier for developers to browse and reference types in their code. The concept of a namespace is not related to that of an assembly. A single assembly may contain types whose hierarchical names have different namespace roots, and a logical namespace root may span multiple assemblies. In the .NET Framework, a namespace is a logical design-time naming convenience, whereas an assembly establishes the name scope for types at run time.