Enjoying the Internet
Using iCloud Online Services
An iCloud account gives you access to a number of useful services and online applications. Because your iCloud account is integrated with OS X, iCloud extends your MacBook Air's desktop onto the Internet.
You can use iCloud to keep information and documents in sync among several devices, such as your MacBook Air, other Macs, an iPhone, an iPad, and even a Windows PC. An iCloud account provides you with online e-mail, calendars, contacts, documents, photos, and more. You can access this through applications on your MacBook Air and through your iCloud website.