Initialize ObservableCollection C# with Example

ObservableCollection is a collection of type T like List which means that it holds objects of type T. 
From documentation we read that : 
ObservableCollectionrepresents a dynamic data collection that provides notifications when items get 
added, removed, or when the entire list is refreshed. 
The key difference from other collections is that ObservableCollection implements the interfaces 
INotifyCollectionChanged and INotifyPropertyChanged and immediately raise notification event when a new 
object is added or removed and when collection is cleared. 
This is especially useful for conneting the UI and backend of an application without having to write extra code 
because when an object is added to or removed from an observable collection, the UI is automatically updated. 
The first step in order to use it is to include 
using System.Collections.ObjectModel 
You can either create an empty instance of a collection for example of type string 
ObservableCollection collection = new ObservableCollection(); 
or an instance that is filled with data 
ObservableCollection collection = new ObservableCollection() 
{ 
"First_String", "Second_String" 
}; 
Remember as in all IList collection, index starts from 0 (IList.Item Property).