A Fragment is a piece of an application's user interface or behavior that can be placed in an Activity which enable more modular activity design. It will not be wrong if we say, a fragment is a kind of sub-acitivity.
Following are important points about fragment:
- A fragment has its own layout and its own behavior with its own
lifecycle callbacks.
- You can add or remove fragments in an
activity while the activity is running.
- You can combine multiple fragments in a single activity to build a multi-pane UI.
- A fragment can be used in multiple activities.
- Fragment life cycle
is closely related to the lifecycle of its host activity which means
- when the activity is paused, all the fragments available in the
acivity will also be stopped.
- A fragment can implement a behavior
that has no user interface component.
- Fragments were added to the
Android API in Honeycomb version of Android which API version 11.
for more details please visit official site.
http://developer.android.com/guide/components/fragments.html