How to Download an iPhone App to Your Computer
When you find an app on the iTunes Store that you’d like to try, just click its Get App button. At that point, you have to log in to your iTunes Store account, even if the app is free.
After you’ve logged in, the app begins downloading. When it’s finished, the app appears in the Applications section of your iTunes Library.

Apps you’ve downloaded appear in the Applications section of your iTunes Library.
Remember that downloading an app to your iTunes Library is only the first half of getting it onto your iPhone. After you download an app, you have to sync your iPhone before the app will be available on it.

iPhone Glossary
FaceTime
Apple software that enables users with supported mobile devices to both see and hear each other during wireless conversations.

iPhone Glossary
iCal
Apple’s personal calendar application.

iPhone Glossary
iCloud
Apple’s wireless storage and synchronization service that keeps digital information updated automatically and wirelessly without user instigation.

iPhone Glossary
iOS 5
The operating system for mobile Apple devices released in June, 2011. With iOS 5, data updates and synchronization occur wirelessly through the iCloud.

iPhone Glossary
jailbreak
Altering an electronic device to remove default restrictions imposed by the manufacturer.

iPhone Glossary
Siri
A voice-controlled personal assistant application purchased by Apple and available exclusively on the iPhone 4S.