Hi Anandita, driver.get() method is used to open an URL and it will wait till the whole page gets loaded. WebDriver will wait until the page has fully loaded before returning control to your test or script. Now note that if a webpage uses a lot of AJAX on load then WebDriver may not know when it has completely loaded. If you need to ensure such pages are fully loaded then you can use waits. For eg:
While driver.navigate.to() method navigates to an URL and It will not wait till the whole page gets loaded. It maintains the browser history and cookies, so we can use forward and backward button to navigate between the pages during the coding of Testcase.