Use of Actions class in Selenium Webdriver - selenium

Question

I was going through the selenium learning and when I was exploring Handling Windows and frames topic in the text, I found this code. Is it necessary to instantiate the Actions class and why we need to do that if we have never going to use it in the code?
public class SwitchBetweenFrames {
public static void main(String... args) {
WebDriver driver = new FirefoxDriver();
driver.get("file://C:/Frames.html");
Actions action = new Actions(driver);
driver.switchTo().frame(0);
WebElement txt = driver.findElement(By.name("1"));
txt.sendKeys("I'm Frame One");
driver.switchTo().defaultContent();
driver.switchTo().frame(1);
txt = driver.findElement(By.name("2"));
txt.sendKeys("I'm Frame Two");
}
}

Answer 1

No, we do not need the Action if nor required. Switching to frame or alert is different and using Action is different concept.
You can use different functions of Action class
http://selenium.googlecode.com/git/docs/api/java/org/openqa/selenium/interactions/Actions.html
And for switch is only used to shift control of webdriver from one page to another or one frame to another

Answer 2

No, it isn't a necessary step to instantiate Actions class, unless there is an actual need of it. For your code, it's not needed at all. Your code will still work, if you comment that section out.
Usually, Actions class can be used to emulate some user gestures, like: drag and drop, click and hold, etc., that by normal standards, is a tad tricky to implement.

Answer 3

No, it is not necessary to user Action class for passing control to a window. For Frames we are just passing the control to another frame. So SwitchTo is used.
Action classes are commonly used for mouse hover actions, drag and drop, click and hold etc like that.
If you want to know more about action class, check the link,
Actions class