Intent and Intent Types-Explicit Intent & Implicit Intents

 See more basics on Android 

All the components are activated by a message called Intents. Intents bind individual components to each other at runtime, whether the component belongs to your application or another. An intent is created with an Intent object, which defines a message to activate either a specific component or a specific type of component—an intent can be either explicit or implicit, respectively.
An intent is an abstract description of an operation to be performed. Intents are send to the Android system via a method call, e.g. via the startActivity() method. They can be said as a message which allow android components to request functionality from other components.

Intent Filters: Activities and intent receivers include one or more filters in their manifest to describe what kinds of intents or message they can handle or want to receive.An intent filters lists a set of requirements, such as datatypes,action requested and URI format that the intent or message must fulfil.

Types Of Intents:
Implicit Intents :
Implicit Intents have not specified a component; instead, they must include enough information for the system to determine which of the available components is best to run for that intent.

Button browserview= (Button)findViewById(R.id.bview);
browserview.setOnClickListener(new OnClickListener() {
 public void onClick(View v) {
   Intent browserintent = new Intent(Intent.ACTION_VIEW, Uri.pars("http://www.http://eazyprogramming.blogspot.in/"));
   startActivity(browserintent);
}
});

Explicit Intent:
Explicit Intents have specified a component, which provides the exact class to be run. Often these will not include any other information, simply being a way for an application to launch various internal activities it has as the user interacts with the application.

Button openclass= (Button)findViewById(R.id.bopenclass);
openclass.setOnClickListener(new OnClickListener() {
 public void onClick(View v) {
   Intent openintent = new Intent(FirstActivity.this,SecondActivity.class));
   startActivity(openintent);
}
});