Mastering Swift 2 Programming (Video 37)

This video tutorial introduces Grand Central Dispatch (GCD) and its dispatch queues, including serial, concurrent, and main queues. It explains the concept of Quality of Service (QoS) classes, such as user interactive, user initiated, utility, and background, and their importance in task prioritization. A practical example demonstrates how to use dispatch queues and QoS classes to optimize code execution, ensuring responsive user interfaces and efficient background processing. The video concludes with a brief overview of the next topic in the series.

Describe the difference between the qos class utility class and the qos class background class.

How can GCD be used to postpone code execution until tasks have completed?