• add(E o) - Appends the specified element to the end of this list.
• add(int index, E element) - Inserts the specified element at the specified position in this list.
• remove(Object obj) - Removes a single instance of the specified element from this collection, if it is present.

For example:

ArrayList<String> myList = new ArrayList<String>();

myList.add ("yes");
myList.add ("no");
myList.add ("maybe");
System.out.println(myList);

The output would be:

[yes, no, maybe]

If we then have:

myList.add ("blue");
myList.add ("red");
myList.remove ("no");
System.out.println(myList);

The output would be:

[yes, maybe, blue, red]

Note: There are many other methods in the ArrayList class than 
what is listed here.  You will learn about them and use them in labs to come.