Can someone explain what getItemCount method in RecyclerView.LayoutManager return?

The documentation says the following about getItemCount():

Returns the number of items in the adapter bound to the parent RecyclerView. Note that this number is not necessarily equal to State#getItemCount().

So, does it return all the items in the adapter or the items that are visible on the screen? I don't get it. Can someone explain this method?

getItemCount() - returns The number of items currently available in adapter

• This method returns the size of the collection that contains the items we want to display.

  @Override
  public int getItemCount() {
      return models.size();
  }
  

• It returns The number of items currently available in adapter.

Reference:

• getItemCount()

• More about layout manager and getItemCount()