Renting a movie in iTunes is one of the cheaper and totally legal alternatives to buying them or getting the flicks on DVD. Just like you used to rent it via the DVD Store or Netflix, iTunes has its own rules that the users need to know so they will not find themselves in a position to rent the movie and not be able to watch it.
First of all, the advantage to renting movies in iTunes is that their catalog has thousands of great titles and they are usually available shortly after the official release in theaters. Also, the back catalog is impressive. Another great advantage is the fact that you can rent a movie on your computer and continue watching it on your Apple TV, iPhone or iPad when you want to.
First word of advice is to make sure your device is compatible. You need to have a computer running iTunes 10 or later and an iOS device with iOS 3.1.3 or newer. That's pretty much any iPad, iPhone and 3rd-generation or newer iPod touch.
When you rent it, the movie goes to your iCloud account. That helps you sync it or later download it to any device. Also, each device remembers where you left off.
You can watch a movie when you are ready. The renter has 30 days to decide when he wants to start the movie. But once you hit play, you need to watch it in the next 24 hours and finish it. If you live outside the United States, you are given a period of 48 hours to watch it.
Once the rental time expires, the movie will be gone from your iTunes library. However, you are not limited to only one viewing in the 24 or 48 hours’ time. You can watch the same movie over and over as many times as you want. That feature is good for kids as you can rent a cartoon and let them watch it over and over during a trip.
It's good to know that you can only watch a rented HD movie only on your computer, iPad, iPhone or later and Apple TV. The rest of your older device will play it in SD. Also, the movie can only exist on one device at a time. You can move it from your iPhone to your iPad, but you cannot watch it on two devices at the same time.