Grand Central Dispatch in Swift

Grand Central Dispatch, or GCD for short, is a low-level C APIs for managing concurrent tasks. It helps us improve our app performance by executing a block of code in reasonable threads, like perform computationally expensive tasks in the background. GCD provides several options for running tasks such as synchronously, asynchronously, after a certain delay, etc.
In this post I will explain more details about GCD and how it works, also provide some interesting points when we work with GCD. Let’s start.