Implicit,Explicit And Fluent Waits

1) Explicit Waits :

An explicit waits is code you define to wait for a certain condition to occur before proceeding further in the code.

Code:

WebDriver driver = new FirefoxDriver();
driver.get("http://somedomain/url_that_delays_loading");
WebElement myDynamicElement = (new WebDriverWait(driver, 10))
.until(ExpectedConditions.presenceOfElementLocated(By.id("myDynamicElement")));

2) Implicit Waits:

An implicit wait is to tell WebDriver to poll the DOM for a certain amount of time when trying to find an element or elements if they are not immediately available. The default setting is 0. Once set, the implicit wait is set for the life of the WebDriver object instance.

Code:

WebDriver driver = new FirefoxDriver();
driver.manage().timeouts().implicitlyWait(10, TimeUnit.SECONDS);
driver.get("http://somedomain/url_that_delays_loading");
WebElement myDynamicElement = driver.findElement(By.id("myDynamicElement"));

3) Using FluentWait :

Selenium webdriver provides FluentWait option to handle uncertain waits. The advantage of this approach is that element polling mechanism is configurable. The code example below waits for 3 second and polls for a textarea every 100 milliseconds.

    FluentWait<By> fluentWait = new FluentWait<By>(By.tagName("TEXTAREA"));  \\ define element for which you want to poll
        fluentWait.pollingEvery(300, TimeUnit.MILLISECONDS); \\ it will ping for every 3 sec
        fluentWait.withTimeout(1000, TimeUnit.MILLISECONDS);  \\ max time out
        fluentWait.until(new Predicate<By>() {
            public boolean apply(By by) {
                try {
                    return browser.findElement(by).isDisplayed();
                } catch (NoSuchElementException ex) {
                    return false;
                }
            }
        });
        browser.findElement(By.tagName("TEXTAREA")).sendKeys("text to enter");

 4) Using WebdriverWait:

Another approach is to use ExpectedCondition and WebDriverWait strategy. The code below waits for 20 seconds or till the element is available, whichever is the earliest.

      public ExpectedCondition<WebElement> visibilityOfElementLocated(final By by) {
        return new ExpectedCondition<WebElement>() {
          public WebElement apply(WebDriver driver) {
            WebElement element = driver.findElement(by);
            return element.isDisplayed() ? element : null;
          }
        };
      }
      
      public void performSomeAction() {
        ..
        ..
        Wait<WebDriver> wait = new WebDriverWait(driver, 20);
        WebElement element = wait.until(visibilityOfElementLocated(By.tagName("a")));
        ..        
      }

Always try to avoid the Thread.sleep or any sleep method method in your code. if you are facing problem about slow execution of application, internet speed is slow. then try to put the wait in more logical way such as put wait in loops for certain seconds and try to perform the action again. this will minimize your execution time.