External Storage - benefits and problems

See below for iCloud


These are some of the notes currently available on Wikipedia. The original should be consulted for up-to-date comprehansive information: https://en.wikipedia.org/wiki/Dropbox_(service)

Dropbox is a file hosting service operated by American company Dropbox, Inc., headquartered in San Francisco, California, that offers cloud storage, file synchronization, personal cloud, and client software. Dropbox was founded in 2007, by MIT students Drew Houston and Arash Ferdowsi, as a startup company, with initial funding from seed accelerator Y Combinator.

Dropbox can create a special folder on the user's computer, the contents of which are then synchronized to Dropbox's servers and to other computers and devices that the user has installed Dropbox on, keeping the same files up-to-date on all devices.

Dropbox Basic users are given 2 gigabytes of free storage space. Dropbox Plus users are given 1 terabyte of storage space, as well as additional features, including advanced sharing controls, remote wipe, and an optional Extended Version History add-on.

Dropbox offers computer apps for Microsoft Windows, Apple macOS, and Linux computers, and mobile apps for iOS, Android, and Windows Phone smartphones and tablets.

In March 2013, the company acquired Mailbox, a popular email app, and in April 2014, the company introduced Dropbox Carousel, a photo and video gallery app. Both Mailbox and Carousel were shut down in December 2015, with key features from both apps implemented into the regular Dropbox service.

In October 2015, it officially announced Dropbox Paper, its collaborative document editor, in a reported effort to expand its operations towards businesses. As of March 2016, Dropbox has 500 million users.

Business model

Dropbox uses a freemium business model, where users are offered a free account with a set storage size, with paid subscriptions available that offer more capacity and additional features.

Dropbox Basic users are given 2 gigabytes of free storage space. This can be expanded through referrals; users recommend the service to other people, and if those people start using the service, the user is awarded with additional 500 megabytes of storage space. Dropbox Basic users can earn up to 16 gigabytes through the referral program.

The Dropbox Plus subscription (named Dropbox Pro prior to March 2017) gives users 1 terabyte of storage space, as well as additional features.

Privacy and security concerns

Dropbox has been the subject of criticism and controversy related to multiple incidents, including:

  • a June 2011 authentication problem that let accounts be accessed for several hours without passwords,
  • a July 2011 Privacy Policy update with language suggesting Dropbox had ownership of users' data, concerns about Dropbox employee access to users' information,
  • July 2012 email spam with recurrence in February 2013,
  • leaked government documents in June 2013 with information that Dropbox was being considered for inclusion in the National Security Agency's PRISM surveillance program,
  • a July 2014 comment from NSA whistleblower Edward Snowden criticizing Dropbox's encryption,
  • the leak of 68 million account passwords on the Internet in August 2016, and
  • a January 2017 accidental data restoration incident where years-old supposedly deleted files reappeared in users' accounts.


The Dropbox software enables users to drop any file into a designated folder. The file is then automatically uploaded to Dropbox's cloud-based service and made available to any other of the user's computers and devices that also have the Dropbox software installed, keeping the file up-to-date on all systems.

When a file in a user's Dropbox folder is changed, Dropbox only uploads the pieces of the file that have been changed, whenever possible.

When a file or folder is deleted, users can recover it within 30 days. For Dropbox Plus users, this recovery time can be extended to one year, by purchasing an "Extended Version History" add-on.

Dropbox accounts that are not accessed or emails not replied in a year are automatically deleted.



Apple’s iCloud file services originally began as cloud storage for your iWork files. With the introduction of OS X Yosemite, it expanded to offer you storage of files and folders beyond iWork. In fact you can now access your Desktop and Documents folders in the cloud and on other devices. But in this article we are going to focus on the sharing features. As each macOS update has come along, Apple has continued to expand its iCloud offerings. (From https://appleusergroupresources.com/how-to-icloud-sharing/#more-13889).


Notes from wikipedia at https://en.wikipedia.org/wiki/ICloud


The cloud-based system allows users to store heterogenous music, photos, applications, documents, bookmarks, reminders, backups, notes, iBooks, and contacts, and provides a platform for Apple's email servers and calendars. Third-party iOS and macOS app developers are able to implement iCloud functionality in their apps through the iCloud API.

Backup and restore

iCloud allows users to back up the settings and data on iOS devices running iOS 5 or later.

Data backed up includes photos and videos in the Camera Roll, device settings, app data, messages (iMessage, SMS, and MMS), ringtones, and Visual Voicemails.

Backups occur daily when the device is locked and connected to Wi-Fi and a power source.

In case of a malfunction of any Apple device, during the restoration process, iCloud offers to restore all data along with App data only if the device was synced to iCloud and backed up.

Back to My Mac is part of iCloud. This service allows users to log in remotely to other computers that have Back to My Mac enabled and are configured with the same Apple ID.


An iCloud account includes an email account. An email address is an optional part of an iCloud account, in that the user can choose not to use it but can still use the email as their iCloud Apple ID.

The email account can be accessed using any standard IMAP-compatible email client, as well as the online web app mail client at the iCloud.com.

Additionally, on an iOS device, iCloud email is push-enabled.

Users converting existing MobileMe accounts to iCloud accounts kept their existing "@me.com" email addresses, and users whose accounts pre-dated MobileMe and had both me.com and mac.com email addresses kept both. As with the .Mac to MobileMe transition, existing users get to keep their old addresses and also get a matching new iCloud.com address, so messages sent to a valid account with multiple addresses all end up in the same inbox.

Find My Friends

Find My Friends was introduced in iOS 5. Find My Friends is very similar to Find My iPhone, except users can share their location with other friends or family using the feature. Concurrently with the launch of iOS 5, Apple released an app for Find My Friends. iOS 6 added location-based alerts to notify the user when a device arrives at a certain location.

In iOS 9 Find My Friends Is built into the device and cannot be removed. In October 2015, Find My Friends was added to iCloud.com to view other "friends" locations.

Find My iPhone

Find My iPhone allows users to track the location of their iOS device or Mac. A user can see the device's approximate location on a map (along with a circle showing the radius depicting the margin of error), display a message and/or play a sound on the device (even if it is set to silent), change the password on the device, and remotely erase its contents.

The feature was first announced on June 10, 2009 and was included in iOS 3.0 software update as a feature for paying MobileMe users. Find My iPhone was made free of charge with the iOS 4.2.1 software update on November 22, 2010, but only for devices introduced in 2010. An iOS app was also released by Apple on June 18, 2010, which allows users to locate their device from other iOS devices running iOS 4 or later software. In iOS 5, Find My iPhone was continued as a feature for iCloud.

iOS 6 introduced Lost Mode, a new feature that allows the user to mark a device as "lost", making it easier to protect and find. The feature also allows someone that finds the user's lost iPhone to call the user directly without unlocking it. Similar phone finder services under various names are available for other families of smartphones.

Activation Lock was introduced in 2013 with iOS 7. It is integrated with iCloud and Find My iPhone feature. This new feature locks the activation of any iPhone, iPad, iPod touch or Apple watch which has been restored in either DFU or Recovery mode without first disabling the Find My iPhone feature.

Once restore is completed, the device will ask for the Apple ID and password that has been previously associated with it, in order to proceed with activation, ultimately preventing any stolen device from being usable. As of iOS 9, Find my iPhone is a built-in app, and thus cannot be removed.

iCloud Keychain

iTunes Match debuted on November 14, 2011. It was initially available to US users only. For an annual fee, customers can scan and match tracks in their iTunes music library, including tracks copied from CDs or other sources, with tracks in the iTunes Store, so customers do not have to repurchase said tracks.

Customers may download up to 100,000 tracks in 256 kbit/s DRM-free AAC file format that match tracks in any supported audio file formats in customers' iTunes libraries, including ALAC and MP3. Customers also have the choice to keep their original copies stored on their computers or have them replaced by copies from the iTunes Store.

Any music not available in the iTunes Store is uploaded for download onto customers' other supported devices and computers; doing this will not take storage from the customers' iCloud's storage allowance. Any such tracks stored in the higher quality lossless audio ALAC, or original uncompressed PCM formats, WAV and AIFF, are transcoded to 256 kbit/s DRM-free AAC format before uploading to the customers' iCloud storage account, leaving the original higher quality local files in their original format.

If a user stops paying for the iTunes Match service, all copies of the DRM-free AAC iTunes Store versions of tracks that have already been downloaded onto any device can be kept, whether on iOS devices or computers.

From iOS 7 and OS X Mavericks, the iTunes Radio function will be available across devices, including integration with the Music app, both on portable iOS devices and Apple TV (2nd generation onwards), as well as inside the iTunes app on Macintosh and Windows computers. It will be included in an ad-free version for subscribers to the iTunes Match service and is currently available only in the US and Australia.

The streaming Genius shuffle is not available in current versions of iOS but is available in iTunes on the Mac. On January 28, 2016, ad-free iTunes Radio was discontinued and is therefore no longer part of iTunes Match. As of March 26, 2014, iTunes Match is available in 116 countries, while iTunes in the Cloud is available in 155 countries.

iWork for iCloud

During the 2013 Apple Worldwide Developers Conference (WWDC) keynote speech, iWork for iCloud was announced for release at the same time as the next version of the app versions of iWork later in the year.

The three apps for both iOS and macOS that form Apple's iWork suite (Pages, Numbers, and Keynote), will be made available on a web interface (named as Pages for iCloud, Numbers for iCloud, and Keynote for iCloud respectively), and accessed via the iCloud website under each users iCloud Apple ID login.

They will also sync with the users iOS and macOS versions of the app, should they have them, again via their iCloud Apple ID. This allows the user to edit and create documents on the web, using one of the supported browsers; currently Safari, Chrome, and Internet Explorer. It also means that Microsoft Windows users now have access to these native–previously only Apple device–document editing tools, via the web interface.

Photo Stream

Photo Stream is a service supplied with the basic iCloud service which allows users to store the most recent 1,000 photos on the iCloud servers up to 30 days free of charge.

When a photo is taken on a device with Photo Stream enabled, it is automatically uploaded to the iCloud servers; from there, it is automatically pushed to the rest of the user's registered devices. Photos in Photo Stream will automatically be removed from other devices after the user reaches the 1,000-photo or 30-day limit.

Users who utilize Photo Stream on their Mac or PC can choose to have all photos permanently saved on their computer — their photos in Photo Stream will not be removed from the computer when they are dropped out of Photo Stream after the user reaches the 1,000-photo or 30-day limit. The service is also integrated with Apple TV, allowing users to view their recent photos wirelessly on their HDTV.

iCloud Photo Library

iCloud Photo Library is a feature on iOS 8.1 or later and OS X Yosemite (version 10.10) of later, plus web app access. The service stores all of the user's photos, maintaining their original resolution and metadata. Users can access their iCloud Photo Library on supported devices via the new Photos app when available or via the iCloud Photo Library web app at iCloud.com, which helps limit the amount of local storage each device needs to use in order to store photos (particularly those with smaller storage capacities) by storing lower-resolution versions on the device, with the user having the option to keep some/all stored locally at higher resolution.

Storage See also: Apple ID

Since introduction in 2011, each account has 5 GB of free storage for owners of either an iOS device using iOS 5.x or later, or a Mac using OS X Lion 10.7 or later. Users can purchase additional storage for a total of 50 GB, 200GB or 2TB. The amount of storage is shared across all devices per iCloud Apple ID.

Several native features of iCloud use each user's iCloud storage allowance, specifically, Backup and restore, and email, Contacts, and Calendars.

On Macs, users can also store most filetypes into iCloud folders of their choosing, rather than only storing them locally on the machine. While Photo Stream uses the iCloud servers, usage does not come out of the user's iCloud storage allowance. This is also true for iTunes Match music content, even for music that is not sold in the iTunes Store and which gets uploaded into iCloud storage, it does not count against the user's allowance.

Other apps can optionally integrate app storage out of the user's iCloud storage allowance. Not all of a user's content counts as part of their iCloud storage allowance.

Apple is able to keep a permanent track of every purchase a user makes under their Apple ID account, and by associating each piece of content with the user, means only one copy of every Store item is needed to be kept on Apple's servers.

For items bought from the iTunes Store (music, music videos, movies, TV shows), iBooks Store (books), or App Store (iOS apps), this uses a service Apple call iTunes in the Cloud, allowing the user to automatically, or manually if preferred, re-download any of their previous purchases on to a Mac, PC, or iOS device.

Downloaded (or streamed, provided the user is connected to the Internet) iTunes Store content can be used across all these devices, however while iBooks Store and App Store content can be downloaded to Macs and PCs for syncing to iOS devices, only iOS and Mac devices — and their respective apps — can be used to read the books. Similarly, macOS apps purchased from the Mac App Store are also linked to the Apple ID they were purchased through, and are able to be downloaded to any Mac using the same Apple ID. Also, when a user registers any new device, all previously bought Store content can be downloaded from the Store servers, or non-Store content from the iCloud servers.

iCloud Drive

iCloud Drive is iCloud's file hosting service for devices running iOS 8, OS X Yosemite (version 10.10), or Windows 7 or later, plus online web app access via iCloud.com. This feature allows users to store any kind of file, including photos, videos, documents, music, and other apps' data, in iCloud Drive and access it on any Mac, iPad, iPhone, iPod Touch, or Windows PC.

Users can start their work on one device and continue on another device.

By default, users will still get 5 GB of storage for free as previously, but the expandable storage plans available have increased considerably in size (up to 2 TB of space) and altered to monthly subscription options from the yearly ones offered under the previous non-iCloud Drive service. In iOS 11, iCloud Drive has been integrated into the new "Files" app, replacing the standalone iCloud Drive app.

Messages on iCloud Messages on iCloud is a feature which keeps all of a user's iMessages and SMS texts stored in the cloud. Messages are synced across Macs, iPhones and iPads.

System requirements

iCloud account creation requires either an iOS device running iOS 5 or later or a Mac running OS X Lion v10.7.5 or later.

Online access to iCloud requires a compatible web browser, and certain features have their own minimum requirements of OS versions. E.g. using iCloud Photo Sharing requires OS X Mavericks v10.9 or above on a Mac.

Devices running older versions of macOS (before Mavericks) or iOS (below 7) may be unable to sign into iCloud after the iCloud password has been changed: the only resolution for this issue is to upgrade the OS, which may be impossible on a device that does not meet the newer OS' minimum requirements.

Synchronizing with a PC requires Windows 7 or later and using the iCloud Control Panel, and optionally Outlook 2007 or later or the built-in Windows 10 Mail and Calendar apps to sync Calendar, Contacts and Reminders. Users must own an Apple device to set up iCloud for Windows.

Synchronization of bookmarks requires Safari 5.1.1 or later on macOS, and Internet Explorer 9, Firefox 22 or Google Chrome 28 or later on Windows. MobileMe account users could move their accounts to be an iCloud account, keeping the same account details.


iCloud has been criticized by third-party developers for bugs that make some features nearly unusable under earlier versions of iOS and macOS, specifically the use of Core Data in iCloud, for storing and syncing larger amounts of data between third party apps on users' devices.

Third-party developers have reported that the changes implemented in the release of iOS 7 and OS X Mavericks (version 10.9) address these iCloud criticisms.

Name dispute

iCloud Communications, a telecommunications company in Arizona, sued Apple in June 2011 for trademark infringement shortly after Apple announced iCloud. The lawsuit was filed in the US District Court of Arizona and demanded that Apple stop using the iCloud name and pay unspecified monetary damages.

iCloud Communications changed its name to Clear Digital Communications in August 2011 and dropped its lawsuit against Apple shortly thereafter.


Apple’s iCloud service, including iCloud Drive and iOS device backups, does not provide end-to-end encryption, also known as client-side encryption, and without end-to-end encryption, user’s information is left unsecured because it remains easily accessible to unauthorized persons.

In August 2014, it was rumored that hackers had discovered an exploit involving the Find My iPhone service, which potentially allowed an attacker to brute-force a user's Apple ID and access their iCloud data. The exploit was later incorrectly rumored to have been used as part of an August 2014 leak of a large number of private, nude photos of celebrities that had been synced to their iCloud storage from their iPhone. Apple confirmed that it was working with law enforcement agencies to investigate the leak.

Apple subsequently denied that the iCloud service itself or the alleged exploit was responsible for the leak, asserting that the leaks were the result of a very targeted phishing attack against the celebrities. On September 13, 2014 Tim Cook, while being interviewed by Charlie Rose, stated on camera that the celebrity leaks were not an iCloud exploit at all, but rather the celebrities had been phished by very targeted phishing to trick them out of their login credentials. Subsequently, when announcing Apple Pay, Apple CEO Tim Cook announced a raft of measures to beef up security including promoting increased awareness of their two-factor authentication process.

Data loss

A bug in iCloud Drive can result in data loss. For example, moving a set of files from iCloud Drive if they have not been synchronized yet will result in their being lost.