title: what is diff b/w Synchronous and asynchronous requests ,How check this operations programmatically
body: <p>Hi i am beginner in ios and when ever we are calling services using NSURLRequest i want to know want to know what happening when we are calling services with "Synchronous request" and calling services with asynchronous request programmatically,
  Please explain that operations programmatically and i have written some code in below  using that code explain Synchronous and asynchronous operations</p>
  
  <h2>my code:-</h2>
  
  <pre><code>- (void)viewDidLoad {
      [super viewDidLoad];
  
   NSURL *url = [NSURL URLWithString:@"http://api.kivaws.org/v1/loans/search.json?status=fundraising"];
          NSMutableURLRequest *theRequest = [NSMutableURLRequest requestWithURL:url];
  
          [theRequest setHTTPMethod:@"GET"];
          [theRequest setValue:@"application/json" forHTTPHeaderField:@"Accept"];
          [theRequest setValue:@"application/json" forHTTPHeaderField:@"Content-Type"];
          [theRequest setTimeoutInterval:5];
  
          NSURLConnection *connection = [[NSURLConnection alloc] initWithRequest:theRequest delegate:self];
  
          if(connection){
  
              webData = [[NSMutableData alloc] init];
          }
  }
  
  - (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response {
  
      [webData setLength:0];
  }
  
  - (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data {
  
      [webData appendData:data];
  }
  
  - (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error {
  
      NSLog(@"error is %@",[error localizedDescription]);
  }
  
  - (void)connectionDidFinishLoading:(NSURLConnection *)connection {
  
      NSString * allDataDictionbary = [[NSString alloc] initWithData:webData encoding:NSUTF8StringEncoding];
  
      NSArray * responseString = [allDataDictionbary JSONValue];
  
     NSLog(@"final respone dictionary%@",responseString);
     }
  </code></pre>