Query about arrayadapter
ArrayAdapter<String> arrayadapter=new 

ArrayAdapter<string>(Sipnner_apActivity.this,android.R.layout.simple_spinner_item,arrarylist);

here what is the meaning of "android.R.layout.simple_spinner_item"    and why Arrayadapter class belong to "widget" class & why not belong to "util" class.thank you.
Query about arrayadapter
===

ArrayAdapter<String> arrayadapter=new 

ArrayAdapter<string>(Sipnner_apActivity.this,android.R.layout.simple_spinner_item,arrarylist);

here what is the meaning of "android.R.layout.simple_spinner_item"    and why Arrayadapter class belong to "widget" class & why not belong to "util" class.thank you.