Object why not use T instead ?

import java.util.*;
  
  public class Test
  {
  		public static void main(String [] args)	
  		{
  					List<Object> staff = new LinkedList<Object>();
  					staff.add("abc");
  					staff.add("efg");
  					staff.add("opq");
  					
  					Iterator it = staff.iterator();
  					Object first = it.next();
  					Object second = it.next();
  		}
  }
  
  class A<T>
  {
  	 private T name;
  }

This program does not make sense , is to practice grammar , why in the class can be used to indicate the type of T in the main why not use T instead of Object, not both said they did not limit the type of it?
------ Solution ---------------------------------------- ----
in a strongly typed language java T is referring to generics, generic meaning is beginning to know the type , like in the time do not need to use the cast operator then can while avoiding usage type of security and other issues .

For example, there is a bag, the bag I knew in advance must be put book , so I can define the class of such a package Bag

class Bag<T>{
   public T getItem();
  }

then to declare an object schoolbag
Bag bag = new Bag ();
So, when you use bag.getItem (), is directly accessible to the Book object.
------ Solution ---------------------------------------- ----
Java generics is the type erasure , both Java generics eventually became Object.
------ For reference only -------------------------------------- -


I'm not sure it should be , I'll express it,

The following two procedures

import java.util.*;
  
  public class Test
  {
  		public static void main(String [] args)	
  		{
              A<String> a = new A<String>();
  
  		}
  }
  
  class A<Object>
  {
  	 private Object name;
  }

import java.util *.;

public class Test
{
public static void main (String [] args)
{
A a = new A ();

}
}

class A
{
private T name;
}

In class A, I Object and T can be compiled through . So I want to ask why the circumstances under which the process can be reversed, why I started the program in the main, are not interchangeable ?
------ For reference only -------------------------------------- -


still do not understand . Object is not to say that you can replace the T, but T is not a substitute Object?