Hey Amanprit, Navigation Commands are used to navigate through the web browser on a webpage. By using these commands, you can go Forward or Backward on a Webpage. You can also refresh a webpage. Following sample test script shows how navigation commands can be used:
import org.openqa.selenium.WebDriver;
import org.openqa.selenium.firefox.FirefoxDriver;
public class Navigation_Commands {
     public static void main(String[] args) throws InterruptedException {
        System.setProperty("webdriver.gecko.driver", "D:\\geckodriver.exe");
        WebDriver driver = new FirefoxDriver();
        driver.get("https://www.edureka.co/");
        driver.navigate().to("https://www.edureka.co/all-courses");
        Thread.sleep(5000);
        driver.navigate().back();
        Thread.sleep(5000);
        driver.navigate().forward();
        Thread.sleep(5000);
        driver.navigate().refresh();
    }
}