Why dispatch_sync( ) call on main queue is blocking the main queue?

Question

I know this is not a strong question but I have to clear my mind on this concept.

I have defined myBlock as follows.

void(^myBlock)(v         


        

Answer 1

Just need to understand this:

dispatch_sync() blocks the dispatch queue, submit the block to it and waits until the submitted block completes.

dispatch_async() submits the block for asynchronous execution on dispatch queue and returns immediately.