JFrame is class of swing package in java and swing package is a part of j2se to develop standalone application.

Here below I am Creating a frame with single argument constructor of the JFrame where I have declared the title of the frame. Next, I am creating a JPanel, JPanel is another type of container. in which panel we are adding other components and the panel itself will be added to the frame.

package com.findnerd;
import java.awt.FlowLayout;
import javax.swing.*;
public class TestFrameExample {

    public static void main(String s[]) {

        JFrame frame = new JFrame("JFrame Example");

        JPanel panel = new JPanel();
        panel.setLayout(new FlowLayout());
        JLabel label = new JLabel("This is a label! Bhagwan Singh");
        JButton button = new JButton();
        button.setText("Press me");

        panel.add(label);
        panel.add(button);
        frame.add(panel);

        frame.setSize(300, 300);
        frame.setLocationRelativeTo(null);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setVisible(true);
 }
}