# Introduction


## Activity

Activity life cycle normally

```
onCreate ->
onStart ->
onResume -> ...
```

After we roate the device screen, the life cycle will continue as below...

```
onSaveInstanceState –>
onPause –>
onStop –>
onDestroy –>
onCreate –>
onStart –>
onRestoreInstanceState –>
onResume –> ...
```

Then we rotate again...

```
onSaveInstanceState –>
onPause –>
onStop –>
onDestroy –>
onCreate –>
onStart –>
onRestoreInstanceState –>
onResume –>
onSaveInstanceState –>
onPause –>
onStop –>
onDestroy –>
onCreate –>
onStart –>
onRestoreInstanceState –>
onResume –>
```

## Fragment