what is .NET Class Library

The .NET Class Library
The .NET class library is a giant repository of classes that provide prefabricated functionality
for everything from reading an XML file to sending an e-mail message. If you’ve had any exposure
to Java, you may already be familiar with the idea of a class library. However, the .NET
class library is more ambitious and comprehensive than just about any other programming
framework. Any .NET language can use the .NET class library’s features by interacting with the
right objects. This helps encourage consistency among different .NET languages and removes
the need to install numerous components on your computer or web server.
Some parts of the class library include features you’ll never need to use in web applications
(such as the classes used to create desktop applications with the Windows interface).
Other parts of the class library are targeted directly at web development. Still more classes can
be used in various programming scenarios and aren’t specific to web or Windows development.
These include the base set of classes that define common variable types and the classes
for data access, to name just a few. You’ll explore the .NET Framework throughout this book.
You can think of the class library as a well-stocked programmer’s toolkit. Microsoft’s philosophy
is that it will provide the tedious infrastructure so that application developers need
only to write business-specific code. For example, the .NET Framework deals with thorny
issues like database transactions and concurrency, making sure that hundreds or thousands of
simultaneous users can request the same web page at once. You just add the logic needed for
your specific application.