we can simplify junit and selenium comparision as follow :--

• Junit is used majorly to test server side/backend/Custom API unit testing, for ex: you make use of junit apis along with java code to test your backend logic by writing small parameteriasied method to check your code logic. Junit is also used with Selenium to automate everything.

   +++++++++++++++ **Sample Junit test Case** +++++++++++++++++++
   import org.junit.Test;
   import static org.junit.Assert.*;
   public class jUnitTestCase{
       @Test
       public void testConcatenation() {
           MyUnit myUnit = new performConcatenation();
           String result = myUnit.concatenate("A", "B");
           assertEquals("AB", result);
       }
   }
   +++++++++++++++ **Sample Custom API to be unit tested** +++++++++++++++
   public class performConcatenation{
       public String concatenate(String A, String B){
           return A+B;
       }
   }
  

• Where as Selenium is a tool (.jar+exe) which you use and then write use case in terms of programming to invoke browser to automate UI testing.

+++++++++++++++ Sample Selenium test Case +++++++++++++++++++

public class LinkedInLogin {

public static void main(String[] args) {
          WebDriver driver=new ChromeDriver(); driver.manage().window().maximize(); 
          driver.get("https://www.linkedin.com/login"); 
          System.out.println("linked in invoked..............");
          WebElement username=driver.findElement(By.id("username")); 
          WebElement password=driver.findElement(By.id("password")); 
          WebElement login=driver.findElement(By.xpath("//button[text()='Sign in']")); 
          username.sendKeys("[email protected]"); password.sendKeys("your inkedIn Password"); 
          login.click(); String actualUrl="https://www.linkedin.com/feed/"; 
}

}

we can simplify junit and selenium comparision as follow :--

• Junit is used majorly to test server side/backend/Custom API unit testing, for ex: you make use of junit apis along with java code to test your backend logic by writing small parameteriasied method to check your code logic. Junit is also used with Selenium to automate everything.

   +++++++++++++++ **Sample Junit test Case** +++++++++++++++++++
   import org.junit.Test;
   import static org.junit.Assert.*;
   public class jUnitTestCase{
       @Test
       public void testConcatenation() {
           MyUnit myUnit = new performConcatenation();
           String result = myUnit.concatenate("A", "B");
           assertEquals("AB", result);
       }
   }
   +++++++++++++++ **Sample Custom API to be unit tested** +++++++++++++++
   public class performConcatenation{
       public String concatenate(String A, String B){
           return A+B;
       }
   }
  

• Where as Selenium is a tool (.jar+exe) which you use and then write use case in terms of programming to invoke browser to automate UI testing.

+++++++++++++++ Sample Selenium test Case +++++++++++++++++++

import org.openqa.selenium.By;
import org.openqa.selenium.WebDriver;
import org.openqa.selenium.WebElement;
import org.openqa.selenium.chrome.ChromeDriver;

public class LinkedInLogin {

public static void main(String[] args) {
          WebDriver driver=new ChromeDriver(); driver.manage().window().maximize(); 
          driver.get("https://www.linkedin.com/login"); 
          System.out.println("linked in invoked..............");
          WebElement username=driver.findElement(By.id("username")); 
          WebElement password=driver.findElement(By.id("password")); 
          WebElement login=driver.findElement(By.xpath("//button[text()='Sign in']")); 
          username.sendKeys("[email protected]"); password.sendKeys("your inkedIn Password"); 
          login.click(); String actualUrl="https://www.linkedin.com/feed/"; 
}

}