Q:

How to block the file download in synchronous with NSURLConnection

im Downloading Synchronously with NSURLConnection i came with this line of code that i dint understand please help me
 can any one explain me this line of code
dispatch_queue_t dispatchQueue =
dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0);

A:

This line of code - using GCD - Grand Central Dispatch.  GCD works by allowing specific tasks in a program that can be run in parallel to be queued up for execution and, depending on availability of processing resources, scheduling them to execute on any of the available processor cores.