Sign on to iCloud from the iCloud.com main webpage using your Apple ID and password. With iCloud, you can access your mail, contacts, calendar, photos, notes and reminders.
To sign into iCloud on an Apple device, such as an iPhone or iPad, go to Settings and then select the iCloud category. From there, you can log into your iCloud account using your Apple ID and password and select which files or information you wish to sync to your iCloud.
With your Apple devices linked to iCloud, you can access your information, pictures and files from a laptop or desktop computer. Using iCloud also allows you to sync those things across multiple Apple devices, so you can access your photos via your iPhone and your iPad if both are linked to your iCloud account.