Hey Anushka, you can use clear() function to reset the value inside the HTML textbox element. Checkout this code snippet to understand better:
WebDriver webdriver = new FirefoxDriver();
webdriver.get("https://www.facebook.com");
webdriver.findElement(By.xpath("//*[@id="email"]")).sendKeys("abha.rathour@edureka.co");
webdriver.findElement(By.xpath("//*[@id="email"]")).clear();