Delegate Means in Objective-C
A delegate allows one object to send messages to another object when an event happens. For example, if you’re downloading data from a web site asynchronously using the NSURLConnection class. NSURLConnection has three common delegates:
– (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error
– (void)connectionDidFinishLoading:(NSURLConnection *)connection
– (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response