GuidAttribute

The GuidAttribute is a metadata attribute in the .NET Framework that allows developers to assign a globally unique identifier (GUID) to a type. This GUID is stored as a string representation of the GUID itself. The primary purpose of the GuidAttribute is to provide a stable and unique way to identify a type, particularly in scenarios where the type might be referenced by its name or assembly location, which could change.

GUIDs are 128-bit values generated to be unique across space and time. By applying the GuidAttribute to a class, struct, or interface, you embed this unique identifier directly into the type's metadata. This can be useful for inter-process communication, serialization, and for ensuring that different versions of the same type can be distinguished.

When a type has a GuidAttribute applied, the GUID can be accessed programmatically through reflection. This allows applications to dynamically discover and interact with types based on their GUID, rather than relying on potentially fragile string-based lookups. The attribute itself is part of the System namespace.