LiveData features -
1.Synchronous
2.Used for notifying
3.No memory leaks
4.No crashes
5.No manual lifecycle handling
6.It acts as a data holder.

Implementation steps -
1.Create LiveData instance to hold certain type of data.Usually done within ViewModel class.
2.Create Observer object that defines onChanged(), which controls what will happen when LiveData object held data changes.
Usually Observer object is created in Activity/Fragment.
3.Attach Observer object to LiveData object using observe() method. observe() takes a LifecycleOwner object.This
subscribes the Observer object to the LiveData object so that it will be notified of changes.