NSURLSessionConfiguration *configuration = [NSURLSessionConfiguration defaultSessionConfiguration]; 
  AFURLSessionManager *manager = [[AFURLSessionManager alloc] initWithSessionConfiguration:configuration]; 
  NSURL *URL = [NSURL URLWithString:@"http://example.com/download.zip"]; 
  NSURLRequest *request = [NSURLRequest requestWithURL:URL]; 
  NSURLSessionDownloadTask *downloadTask = [manager downloadTaskWithRequest:request progress:nil destination:^NSURL *(NSURL *targetPath, NSURLResponse *response) { 
    NSURL *documentsDirectoryURL = [[NSFileManager defaultManager] URLForDirectory:NSDocumentDirectory inDomain:NSUserDomainMask appropriateForURL:nil create:NO error:nil]; 
    return [documentsDirectoryURL URLByAppendingPathComponent:[response suggestedFilename]]; 
  } completionHandler:^(NSURLResponse *response, NSURL *filePath, NSError *error) { 
    NSLog(@"File downloaded to: %@", filePath); 
  }]; 
  [downloadTask resume]; 

 NSURLSessionConfiguration *configuration = [NSURLSessionConfiguration defaultSessionConfiguration]; 
  AFURLSessionManager *manager = [[AFURLSessionManager alloc] initWithSessionConfiguration:configuration]; 
  NSURL *URL = [NSURL URLWithString:@"http://example.com/upload"]; 
  NSURLRequest *request = [NSURLRequest requestWithURL:URL]; 
  NSURL *filePath = [NSURL fileURLWithPath:@"file://path/to/image.png"]; 
  NSURLSessionUploadTask *uploadTask = [manager uploadTaskWithRequest:request fromFile:filePath progress:nil completionHandler:^(NSURLResponse *response, id responseObject, NSError *error) { 
    if (error) { 
      NSLog(@"Error: %@", error); 
    } else { 
      NSLog(@"Success: %@ %@", response, responseObject); 
    } 
  }]; 
  [uploadTask resume]; 

NSMutableURLRequest *request = [[AFHTTPRequestSerializer serializer] multipartFormRequestWithMethod:@"POST" URLString:@"http://example.com/upload" parameters:nil constructingBodyWithBlock:^(id<AFMultipartFormData> formData) { 
      [formData appendPartWithFileURL:[NSURL fileURLWithPath:@"file://path/to/image.jpg"] name:@"file" fileName:@"filename.jpg" mimeType:@"image/jpeg" error:nil]; 
    } error:nil]; 
  AFURLSessionManager *manager = [[AFURLSessionManager alloc] initWithSessionConfiguration:[NSURLSessionConfiguration defaultSessionConfiguration]]; 
  NSURLSessionUploadTask *uploadTask; 
  uploadTask = [manager 
         uploadTaskWithStreamedRequest:request 
         progress:^(NSProgress * _Nonnull uploadProgress) { 
           // This is not called back on the main queue. 
           // You are responsible for dispatching to the main queue for UI updates 
           dispatch_async(dispatch_get_main_queue(), ^{ 
             //Update the progress view 
             [progressView setProgress:uploadProgress.fractionCompleted]; 
           }); 
         } 
         completionHandler:^(NSURLResponse * _Nonnull response, id _Nullable responseObject, NSError * _Nullable error) { 
           if (error) { 
             NSLog(@"Error: %@", error); 
           } else { 
             NSLog(@"%@ %@", response, responseObject); 
           } 
         }]; 
  [uploadTask resume]; 

  NSURLSessionConfiguration *configuration = [NSURLSessionConfiguration defaultSessionConfiguration]; 
  AFURLSessionManager *manager = [[AFURLSessionManager alloc] initWithSessionConfiguration:configuration]; 
  NSURL *URL = [NSURL URLWithString:@"http://httpbin.org/get"]; 
  NSURLRequest *request = [NSURLRequest requestWithURL:URL]; 
  NSURLSessionDataTask *dataTask = [manager dataTaskWithRequest:request completionHandler:^(NSURLResponse *response, id responseObject, NSError *error) { 
    if (error) { 
      NSLog(@"Error: %@", error); 
    } else { 
      NSLog(@"%@ %@", response, responseObject); 
    } 
  }]; 
  [dataTask resume]; 

Request serializers create requests from URL strings, encoding parameters as either a query string or HTTP body.
  NSString *URLString = @"http://example.com"; 
  NSDictionary *parameters = @{@"foo": @"bar", @"baz": @[@1, @2, @3]};