CFURL

CFURL is a fundamental Core Foundation framework in macOS and iOS development. It represents a uniform resource locator (URL) and provides a standardized way to manage and access resources across different locations. These resources can be local files on the file system, or remote resources accessible via the internet using protocols like HTTP, FTP, and file.

CFURL objects are immutable, meaning once created, their content cannot be changed. This immutability ensures thread safety and simplifies resource management. The framework offers functions to create CFURL objects from strings, manage their properties (such as the scheme, host, path, and query), and resolve relative URLs against a base URL.

Developers use CFURL to interact with various system services and frameworks that require URL specifications. For instance, when downloading data from a web server using NSURLSession (which internally uses CFURL), or when accessing local files using file paths. The CFURL framework provides a robust and efficient mechanism for handling these resource identifiers, abstracting away the complexities of different networking protocols and file system structures. It plays a crucial role in the overall resource management and networking capabilities of Apple's operating systems.