NSObject subclass

generate a one-sentence description for a given conceptual class.
# Response Format
Return only the sentence: "Description: [one-sentence description of the conceptional class]"

Class: NSObject subclass

An NSObject subclass is a custom class in Objective-C (or Swift via bridging) that inherits from the root NSObject class to gain fundamental runtime, memory management, and messaging behavior in the Cocoa/Cocoa Touch frameworks.