Technical notes index
Moving calendars between 'On My Mac' and iCloud
Restoring iCloud calendars from a Time Machine or other backup
iCloud and Snow Leopard
Entering iCloud Mail settings manually in Snow Leopard
Entering iCloud Mail settings manually in Tiger


What is iCloud?
What about MobileMe?
Different IDs for iTunes and iCloud
iCloud, iTunes in the Cloud, and iTunes Match
Can I use iCloud with Snow Leopard?
Web-only account
More Frequently Asked Questions
iCloud facilities
Links to iCloud Help pages

What is iCloud?

iCloud is Apple's online service, introduced in 2011. Pitched in part as a replacement for the now-defunct MobileMe, it's designed to sync your contacts, calendars, bookmarks, photos, and iWork documents between devices. It also allows downloading of music you've purchased from the iTunes Store - in the future or the past - to other devices. (Online storage and downloading of material you've added yourself, for example by ripping CDs, is provided at a charge.)

These facilities are free to users of OSX 10.7.5 'Lion' and above, and iOS5 and above for mobile devices, and these systems are the minimum requirement to set up or transition to an iCloud account. Most facilities are not available to earlier systems, though Mail can be accessed from any email client provided an iCloud has been set up in the first place. There is currently no indication the other facilities will in future be available on Snow Leopard - see below.

It would appear that Support is available only to people with 'AppleCare' - which is free for 90 days after purchasing hardware, or has to be paid for to extend it. You might want to consider whether you should entrust your email to a service which has no support contact should there be problems (though the same probably applies to the other free email services).

What about MobileMe?

As was announced in June 2011, MobileMe was terminated on 1 July 2012. If you had a MobileMe subscription, and did not migrate your email, contacts and calendars to iCloud and your iDisk contents and Gallery to your computer or another hosting service, then you can no longer do so and the contents of your account have been deleted.

If you haven't migrated your account you can treat it as expired and sign in to System Preferences>iCloud with it to open an iCloud account and reactivate the address (but not recover the emails previously stored on it). However if you had both and versions of the address you can only reactivate the version (it's not clear yet whether this is still possible now that new iCloud addresses are the one is no longer viable.

My Apple ID for iTunes and my iCloud login are different

Many people are in this situation because they opened an Apple ID to use with iTunes, the Discussion Forums or hardware registration, and then joined MobileMe or iCloud at a later date - the email address is an Apple ID itself.

You can't merge these two IDs. As you have a different ID for iTunes you should continue to use that for iTunes, iTunes in the Cloud and iTunes Match. There is no problem about using two different IDs in this way; and indeed I think it's preferable, given the number of complaints about hacked accounts on iTunes, not to have your iTunes login the same as your publicly available email address.

iCloud, iTunes in the Cloud, and iTunes Match

It may be helpful to clarify the differences between iCloud, iTunes in the Cloud, and iTunes Match, because re-downloading your songs and movies doesn't actually have anything to do with iCloud - Apple persist in using the name for both and it's confusing a lot of people.
iCloud is your own account which enables syncing of calendar and contacts data, transfer of iWork and TextEdit documents between your devices, transfer of photos taken on one device onto all the others, an email service, and the ability to find a lost device which has been set up correctly. It does not provide general file storage, and it does not store your movies or music. It's free at basic level of 5GB for the items mentioned above with extra storage purchasable.
iTunes in the Cloud does not store anything except in the iTunes Store. It simply recognizes that you have previously purchased an item and allows you to re-download it on other devices, or, as you say, re-download it onto the original device if you've deleted it. No extra storage is required because the items are already in the Store. Complicated rights issues means that not all items are available this way, and that different countries have different availablilities. Also if an item is withdrawn from the Store you won't be able to re-download it even if you already purchased it.
iTunes Match applies to music (not films) in your collection which you did not purchased from the iTunes Store, but downloaded from elsewhere or ripped from your CDs. If the item exists in the Store it allows you to download a version from there; if not you can upload it to space allocated for you. This facility costs  $24.99/21.99 per year, limit 25,000 songs (purchases do not count towards this limit). This is not part of the iCloud 5GB free storage.
iTunes in the Cloud and iTunes Match require an iTunes account; they do not require an iCloud account.

Can I use iCloud with Snow Leopard?

Officially, no: Lion 10.7.5 is required. If you have already opened an iCloud account on a Lion Mac or an iOS5 device you can set Mail up manually to access  email on Snow Leopard or Leopard, or on Tiger; you can't open a new account on older systems than Lion or OS5.

This page lists the situation when trying to use iCloud in Snow Leopard in more detail, including a few workarounds and some third-party software which may be of interest.

Web-only account
You can create a 'web-only' account by signing in with an Apple ID at; this has only 1GB of free storage and limited facilities, in particular no email. You can upgrade it to a standard account with 5GB of free storage and full facilities by signing in in the iCloud pane of System Preferences/Settings on a Mac or an iOS device (not Windows or Android). The information in this page applies to the standard version.

There are more Frequently Asked Questions (and their answers) here.

iCloud facilities

The table below lists iCloud's facilities. OSX 10.7.5 and iOS5 are the minimum requirement.
An address is provided, together with up to 3 'aliases' (additional addresses). (People who already have and address will retain them but new ones cannot be created.) Webmail is provided. Mail storage counts towards your free 5GB space (upgradeable, see bottom of table). Note that automatic spam filtering is applied, which it is admitted may cause occasional false positives and consequent silent deletion.
This facility is not available.
Contacts are automatically synced to your other devices.
iCal Calendars sync to iCloud and from there to other devices. Pre-Lion Macs cannot sync with it: an unofficial method of syncing Snow Leopard's iCal has been published: use at your own risk.
Photos can be shared privately to invitees or by enabling 'Public Website' to a generally available website gallery.
A conduit for syncing photos to your other devices: all photos on Macs, last 1,000 on iOS devices. Photos held in the cloud for maximum 30 days, and not available to other people. Does not count towards your free 5GB space. Shared Photo Streams enable you to share selected photos with other iCloud users (Mountain Lion 10.8.2 or iOS6, and iPhoto 9.4 or Aperture 3.4 required).
Backup of Apps, books, music, photos, settings, SMS & MMS messages and ringtones from your iOS devices (not backup from your Mac). Counts towards your free 5GB space (upgradeable, see bottom of table).
Is available in iCloud, enabling you to locate a lost phone provided it is on and able to connect to a network.
Is available in iCloud, enables you to allow friends to see where you are (temporarily if required) and vice versa (with their permission).
iCloud does not provide website hosting. See here for alternatives.
This works through the iCloud Drive (see below)
New and past purchases available for download to all your devices. Does not count towards your free 5GB space.
Music in iTunes not purchased in the Store can be uploaded to be available to all devices. $24.99/21.99 per year, limit 25,000 songs (purchases do not count towards this limit). This is not part of the 5GB free storage. Remains available to those who don't subscribe to Apple Music. (Not strictly part of iCloud.)
Streaming and saving for offline listening access to a large proportion of the  iTunes Store music catalogue; $9.99 per month. Songs play only in iTunes. Also includes streaming 'radio stations'. (Not strictly part of iCloud.)
Purchased iBooks from the Bookstore made available to all your devices. Does not count towards your free 5GB space.
Purchased iOS apps are made available to all your iOS devices. Does not count towards your free 5GB space.
Safari Bookmarks syncing is provided in iCloud: bookmarks are not viewable on the iCloud website.
In Mountain Lion or above, Mail Rules, signatures, flag names and Smart Mailboxes are synced if you have 'Documents and Data' syncing enabled. Syncing of Dashboard Widgets, Dock Items, Keychains, and Address Book sharing all ceased with the termination of MobileMe and are not available in iCloud.
Is available, connection to 'AirDisks' has been made available in an update.
With iOS8+, and OSX Yosemite or above, iCloud provides 'Family Sharing' where family members including children can have accounts linked to and controlled by the main account.
A general file storage area (similar to the old iDisk) is  available in iOS8+ and OSX Yosemite or above. If you enable iCloud Drive and don't have Yosemite or above you will not be able to access your documents at - see this note.

With OSX Sierra and iOS10 you can transfer your Desktop and your Documents folder to iCloud so that you can access them on all your devices. More details here.
COST Free for OSX 'Lion' and above and iOS5, including downloading of purchased iTunes songs, and 5GB space for Backup, Mail, Photo Journal, Documents and iCloud Drive if enabled.

Storage and downloading of personally added iTunes songs at $24.99 p.a.

Additional storage (replaces the free 5GB, not adds to it); pricing is charged monthly(there is no annual option). 50GB $0.99 p.m., 200GB $2.99 p.m., 2TB $9.99 p.m. (UK 0.79, 2.49, 6.99; other countries detailed here.)

Here are some useful links to Apple iCloud Help pages:
And a useful page from MacWorld about the two ways of syncing iOS devices:
(Syncing using iTunes was disabled in the early versions of Mavericks but restored in 10.9.3)

Roger Wilmut. This site is not associated with Apple.