diff --git a/jina/helloworld/__init__.py b/jina/helloworld/__init__.py
index 40197d983d909..c0114471ab4ca 100644
--- a/jina/helloworld/__init__.py
+++ b/jina/helloworld/__init__.py
@@ -34,26 +34,36 @@ def hello_world(args):
         }
     }
 
+    # download the data
     download_data(targets)
 
+    # this envs are referred in index and query flow YAMLs
     os.environ['RESOURCE_DIR'] = resource_filename('jina', 'resources')
     os.environ['SHARDS'] = str(args.shards)
     os.environ['REPLICAS'] = str(args.replicas)
     os.environ['HW_WORKDIR'] = args.workdir
     os.environ['WITH_LOGSERVER'] = str(args.logserver)
+
+    # reduce the network load by using `fp16`, or even `uint8`
     os.environ['JINA_ARRAY_QUANT'] = 'fp16'
 
+    # now comes the real work
+    # load index flow from a YAML file
     f = Flow.load_config(args.index_yaml_path)
+    # run it!
     with f:
         f.index(input_fn(targets['index']['filename']), batch_size=args.index_batch_size)
 
+    # wait for couple of seconds
     countdown(8, reason=colored('behold! im going to switch to query mode', 'cyan',
                                 attrs=['underline', 'bold', 'reverse']))
 
+    # now load query flow from another YAML file
     f = Flow.load_config(args.query_yaml_path)
+    # run it!
     with f:
         f.search(input_fn(targets['query']['filename'], index=False, num_doc=args.num_query),
                  output_fn=print_result, top_k=args.top_k, batch_size=args.query_batch_size)
 
-    html_path = os.path.join(args.workdir, 'hello-world.html')
-    write_html(html_path)
+    # write result to html
+    write_html(os.path.join(args.workdir, 'hello-world.html'))