Call Another Activity From one Activity in Android Development

to Open new activity or page
here is the android code to open new activity from one another activity

package com.one.click;//Package name
//libraries want to import
import android.R.string;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.Menu;
import android.view.View;
import android.widget.Button;

public class MainScreenActivity extends Activity{
    
  //Declare a button
    Button btnNewProduct;
    
    //declare a layout which is want to open when this class called
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main_screen);//here is the place to enter layout name
        
        // Buttons assign the id of the buton in our layout
        btnNewProduct = (Button) findViewById(R.id.btnCreateProduct);
      
        
        // here is the place show when click btnNewProduct    buton which class want to open              btnNewProduct.setOnClickListener(new View.OnClickListener() {
            
                       public void onClick(View view) {
                // Launching create new product activity
                Intent i = new Intent(getApplicationContext(), NewProductActivity.class);
                startActivity(i);
                
            }
        });
    }