The .NET framework provides a set of base class libraries which provide functions and features which can be used with any programming language which implements .NET, such as Visual Basic, C# (or course), Visual C++, etc.
The base class library contains standard programming features such as Collections, XML, DataType definitions, IO ( for reading and writing to files), Reflection and Globalization to name a few. All of which are contained in the System namespace. As well, it contain some non-standard features such as LINQ, ADO.NET (for database interactions), drawing capabilities, forms and web support.
The below table provides a list each class of the base class library and a brief description of what they provide.
|Base Class Library Namespace
|Contains the fundamentals for programming such as the data types, console, match and arrays, etc.
|Supports the creation of code at runtime and the ability to run it.
|Contains Lists, stacks, hashtables and dictionaries
|Provides licensing, controls and type conversion capabilities
|Used for reading and writing program configuration data
|Is the namespace for ADO.NET
|Upgrading capabilities via ClickOnce
|Provides tracing, logging, performance counters, etc. functionality
|Is the namespace used to access the Active Directory
|Contains the GDI+ functionality for graphics support
|Used when working with COM+ from .NET
|Supports the localization of custom programs
|Provides connection to file system and the reading and writing to data streams such as files
|Interface to LINQ providers and the execution of LINQ queries
|Namespace which contains delegates and lambda expressions
|Provides access to system information such as CPU utilization, storage space, etc.
|Contains methods to play sounds
|Used when message queues are required within an application, superseded by WCF
|Provides access to network protocols such as SSL, HTTP, SMTP and FTP
|Ability to read, create and invoke class information.
|Used when localizing a program in relation to language support on web or form controls
|Contains functionality which allows the management of runtime behavior.
|Provides hashing and the ability to create custom security systems using policies and permissions.
|Used when a windows service is required
|Provides the StringBuilder class, plus regular expression capabilities
|Contains methods to manage the creation, synchronization and pooling of program threads
|Provides the ability to raise events or take an action within a given timer period.
|Contains methods for the management of transactions
|Namespace for ASP.NET capabilities such as Web Services and browser communication.
|Namespace containing the interface into the Windows API for the creation of Windows Forms programs.
|Provides the methods for reading, writing, searching and changing XML documents and entities.