What is need of creating the list when we have already created the ArrayList to store the JSONArray?

What is the need of creating the list when we have already created the ArrayList to store the JSONArray?
This code is to access the data from the internet which is JSON format, using the volley library. I am having a little problem in understanding the use of ArrayLists along with List. Couldn't we just exclude the List?

//What is the use of the List?

ArrayList<Question> questionArrayList= new ArrayList<>();
public List<Question> getQuestions (){
    JsonArrayRequest jsonArrayRequest =new JsonArrayRequest(Request.Method.GET, url, null,
            new Response.Listener<JSONArray>() {
                @Override
                public void onResponse(JSONArray response) {
                    for(int i=0;i<response.length();i++){
                        Question question = new Question();
                        try {
                            question.setQuestionId(response.getJSONArray(i).getString(0));
                            question.setTorF(response.getJSONArray(i).getBoolean(0));
                            questionArrayList.add(question);//If we had to add the question entries to the questionArrayList then why create a list(getQuestions)?

                        } catch (JSONException e) {
                            e.printStackTrace();
                        }
                    }
                }
            },
            new Response.ErrorListener() {
                @Override
                public void onErrorResponse(VolleyError error) {

                }
            };

//My Question class is this:-

package com.example.trivia.model;

public class Question {

private String QuestionId;
private boolean IsTorF;

public Question(String questionId, boolean isTorF) {
    this.QuestionId = questionId;
    this.IsTorF = isTorF;
}
public Question(){
}
public String getQuestionId() {
    return QuestionId;
}

public void setQuestionId(String questionId) {
    QuestionId = questionId;
}

public boolean isTorF() {
    return IsTorF;
}

public void setTorF(boolean torF) {
    IsTorF = torF;
}

}

You don't have to, its your choice.

UPDATE:

Based on being given the return type of the method ArrayList<Question> this indicates encapsulation. This is very common for creating API's or Repository classes. With the current implementation, let's assume your calling class is expecting to use the data as an ArrayList. No surprise, the return type was of an ArrayList. Now, later in the project we need the data is a LinkedList. You can certainly add code to make that work OR you can implement it as it was, decoupling the implementation of List.

OLD ANSWER:

You should be creating an immutable List for your response to ensure you always have the original response unmodified. In this example the response is getting set to an immutable List as well adding each item out to a mutable list so you can modify the contents. This also reduces another step of iterating over the list later and copying the values since Java is pass-by-reference