Bundles are generally used for passing data between various Android activities. It depends on you what type of values you want to pass, but bundles can hold all types of values and pass them to the new activity.
You can use it like this:
Intent intent = new...
Intent(getApplicationContext(), SecondActivity.class);
intent.putExtra("myKey", AnyValue);
startActivity(intent);
You can get the passed values by doing:
Bundle extras = intent.getExtras();
String tmp = extras.getString("myKey");
You can find more info at:
Pass data between activities by using Bundle and Intent objects.
Your first create a Bundle object
Bundle b = new Bundle();
Then, associate the string data stored in anystring with bundle key "myname"
b.putString("myname", anystring);
Now, create an Intent object
Intent in = new Intent(getApplicationContext(), secondActivity.class);
Pass bundle object b to the intent
in.putExtras(b);
and start second activity
startActivity(in);
In the second activity, we have to access the data passed from the first activity
Intent in = getIntent();
Now, you need to get the data from the bundle
Bundle b = in.getExtras();
Finally, get the value of the string data associated with key named "myname"
String s = b.getString("myname");