There are a few ways in which one can launch intents,

First lets see how you create a basic intent,

new Intent(context, helloactivity.class);

Above is an example of an explicit intent which does not require any intent filter to be present in the android manifest, as the target activity has already been specified as the second parameter.

Another way can be,

new Intent(Intent.ACTION_VIEW,uri);

The uri plays an important role here as described below,

  1. http: or https:, will display a link in the browser.
  2. ge0: used to perform google maps related stuff on appropriately supplied longitude and latitude
  3. tel: or voicemail: for telephony stuff