How to complie

Greetings , I am a newbie java learner , stepped from basic C knowlage
to java at my universty and sadly due to I was sick I missed the latest
course . I am seeking explaining about what this small program do and
how to complie it. When I try to complie it at terminal i am getting
"no suitable method `main' in class
" error. As far as I understood it looks like it will show some
graphics and it is some kind of javaapplet.

Here is the code:
import java.awt.*;
import javax.swing.*;

public class PointArrayApplet extends JApplet
{
    public void paint(Graphics g)
    {
        Point [] triangle;
        triangle=new Point[3];
        triangle[0]=new Point(10,20);
        triangle[1]=new Point(35,90);
        triangle[2]=new Point(75,105);
        g.drawString(triangle[0].toString(),10,20);
        g.drawString(triangle[1].toString(),35,90);
        g.drawString(triangle[2].toString(),75,105);
        translate(triangle,100,200);
        g.drawString(triangle[0].toString(),110,220);
        g.drawString(triangle[1].toString(),135,290);
        g.drawString(triangle[2].toString(),175,305);
    }
    public static void translate(Point []points,int deltaX,int deltaY)
    {
        for(int i=0;i<points.length;i++)
            points[i].translate(deltaX,deltaY);
    }
}

Thanks in advance.