1) In Mozilla Firefox
driver = new FirefoxDriver();
2)In Chrome
System.setProperty("webdriver.chrome.driver",Add absolute path of chromedriver.exe");
driver = new ChromeDriver();
3) In IE
System.setProperty("webdriver.ie.driver","Add absolute path of IEDriverServer.exe");
driver = new InternetExplorerDriver();
4) In Edge
System.setProperty("webdriver.edge.driver",Add absolute path of MicrosoftWebDriver.exe");
EdgeOptions options = new EdgeOptions();
options.setPageLoadStrategy("eager");
driver = new EdgeDriver(options);
5) In Opera
System.setProperty("opera.binary", Add absolute path of opera.exe");
WebDriver driver = new OperaDriver();
6) In Safari
System.setProperty("SafariDefaultPath", Add absolute path of Safari.exe");
WebDriver driver = new SafariDriver();