Difference between Android Framework widgets and their AppCompat version

Question

I have lately noticed that there are AppCompat versions of most View types in Android, for example ListView / ListViewCompat, Button /

Answer 1

AppCompat is support older version of android os like AppCompat-v7 is support from android 6.1.1 to android 2.6.0

for above reason they have created AppCompat classes of below widgets in this support library nothing more.

from Documentation

The full list of tint aware widgets available in appcompart

AppCompatAutoCompleteTextView
AppCompatButton
AppCompatCheckBox
AppCompatCheckedTextView
AppCompatEditText
AppCompatMultiAutoCompleteTextView
AppCompatRadioButton
AppCompatRatingBar
AppCompatSpinner
AppCompatTextView

ListViewCompat is subclass of ListView same others

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edited:

why both class available in framework or How Android Support Library work?