The core types are contained
System namespace. This namespace is the heart of
the FCL and contains classes, interfaces, and attributes that all
other types depend on. The root of the FCL is the type
Object, from which all other .NET types derive.
are ValueType (the base type for structs),
Enum (the base type for enums),
Convert (used to convert between base types),
Exception (the base type for all exceptions), and
the boxed versions of the predefined value types. Interfaces that are
used throughout the FCL, such as ICloneable,
IComparable, IFormattable, and
IConvertible, are also defined here. Extended
types such as DateTime,
TimeSpan, and DBNull are
available as well. Other classes include support for delegates (see
Section 4.1 in Chapter 4), basic math operations, custom attributes
(see Section 4.7 in Chapter 4 and Chapter 14), and
exception handling (see Section 4.6 in Chapter 4).
For more information, see the System namespace.