What is android

Android is an open source which is introduced by the google. It is software package to develop application which can be executed on different device like mobile, tablet etc. Android runs on the Linux kernel system.

What is Activity

Activities are the user interface in android. It provides screens for the android app. A single application can have many activities.

What is Manifests

Every android app must have AndroidManifests xml files in its root directory. It contains the permissions and component used in the app.

What are the properties of layout height and width

Wrap_content :- when you set width as wrap_content then it will take the space according to the content. According to content the width has been changed.

Fill_parent:- fill_parent will take the width according to the layout. Fill_parent replaced by the match_parent in API Level 8

What is progress bar in android

Progress bar is the most important control in android. It is used to display the progress of particular task in android. In android we use ProgressDialog class to create progress bar.

What is event listener

In android an event listener is an interface which is having a callback method which executed when user triggered some event or action like button click, long click, focus etc.

What is Shared Preference

Shared Preference is the way to store user information. In android application if we have requirement to store some small information then we can use shared preference. Data will be stored in key value pair in shared preference.