Grand Central Dispatch tutorial

Grand Central Dispatch (GCD), released by Apple in 2009, is an open-source library designed to manage concurrent task execution efficiently by leveraging multithreading and queues. Operating under the Apache License, GCD ensures that heavy computational tasks are executed in the background, allowing the main thread to remain responsive for smoother user interfaces. It facilitates multithreading by enabling the CPU to switch between tasks, optimizing performance and reducing lag. GCD employs serial and concurrent queues to organize and execute tasks either sequentially or simultaneously, with the main thread handling serial tasks and background threads handling concurrent ones. Developers can use DispatchQueue and DispatchGroup to schedule, manage, and synchronize tasks, enhancing the execution of asynchronous operations. By delegating the management of threads to the operating system, GCD relieves developers from the intricacies of concurrent execution, allowing them to focus on building responsive applications.