WHAT IS CLOUD COMPUTING ?
Ultimately, the "cloud" is just a metaphor for the internet. It goes back to the days of flowcharts and presentations that would represent the gigantic server-farm infrastructure of the internet as nothing but a puffy cloud, accepting connections and doling out information as it floats.
The cloud is also not about having dedicated network attached storage (NAS) device in your house. Storing data on a home or office network does not count as utilizing the cloud. (However, some NAS devices will let you remotely access things over the internet, and there's at least one brand from Western Digital named "My Cloud," just to keep things confusing.)
For it to be considered "cloud computing," you need to access your data or your programs over the internet, or at the very least, have that data synced with other information over the web. In a big business, you may know all there is to know about what's on the other side of the connection; as an individual user, you may never have any idea what kind of massive data processing is happening on the other end in a data center that uses more power in a day than your whole town does in a year. The end result is the same: with an online connection, cloud computing can be done anywhere, anytime.
Consumer vs. Business
Let's be clear here. I'm talking about cloud computing as it impacts individual consumers—those of us who sit back at home or in small-to-medium offices and use the internet on a regular basis.
There is an entirely different "cloud" when it comes to business. Some businesses choose to implement Software-as-a-Service (SaaS), where the business subscribes to an application it accesses over the internet. (Think Salesforce.com.) There's also Platform-as-a-Service (PaaS), where a business can create its own custom applications for use by all in the company. And don't forget the mighty Infrastructure-as-a-Service (IaaS), where players like Amazon, Microsoft, Google, and Rackspace provide a backbone that can be "rented out" by other companies. (For example, Netflix is a customer of the cloud services at Amazon.)
Of course, cloud computing is big business. Our partners at Statista created this chart in February 2020 showing Amazon's dominance in the $100 billion a year business. That, of course, was a month before the COVID-19 coronavirus shut down a lot of businesses—which then transferred their cloud computing to the home, seamlessly for the most part
But that's in the US and thus represents only a slice of the cloud pie. If you take the worldwide use into account, the market is worth far more. It was $272 billion in 2018, and expected to be worth $623.3 billion by 2023, according to Markets and Markets.
Common Cloud Examples
When it comes to home use, the lines between local computing and cloud computing sometimes get blurry. That's because the cloud is part of almost everything on our computers these days. You can easily have a local piece of software (for instance, Microsoft Office) that utilizes a form of cloud computing for storage (Microsoft OneDrive). Microsoft also offers a set of web-based apps, Office (aka Office for the Web), that are web-only versions of Word, Excel, PowerPoint, and OneNote accessed via your web browser without installing anything. That makes them a version of cloud computing (web-based=cloud).
Some other major examples of cloud computing you're probably using:
Google Drive: This is a pure cloud computing service, with all the storage found online so it can work with the cloud productivity apps: Google Docs, Sheets, and Slides. Google Drive is also available on more than just desktop computers; you can use it on tablets like the iPad or on smartphones, which have separate apps for Docs and Sheets, as well. In fact, most Google services could be considered cloud computing: Gmail, Google Calendar, Google Maps, and so on.
Apple iCloud: Apple's cloud service is primarily used for online storage, backup, and synchronization of your mail, contacts, calendar, and more. All the data you need is available to you on your iOS, iPadOS, macOS, or Windows devices (Windows users have to install the iCloud control panel). Naturally, Apple won't be outdone by rivals: it offers cloud-based versions of its word processor (Pages), spreadsheet (Numbers), and presentations (Keynote) for use by any iCloud subscriber. iCloud is also the place iPhone users go to utilize the Find My iPhone feature when the handset goes missing.
Dropbox: This service has been a simple, reliable file-sync and storage service for years, but is now enhanced with lots of collaboration features (which will cost you and your business, as the free version has gotten a bit skimpy).
Slack: Yes, it's considered cloud computing if you have a community of people with separate devices that need instant messaging/communication. The poster child for that is Slack, but you get the same from Microsoft Teams, Workplace by Facebook, and more. Read about them in 17 Alternatives to Slack.
The aforementioned file-synchronization/backup service, and others like Box, IDrive, and SugarSync all work in the cloud because they store a synced version of your files online, but they also sync those files with local storage. Synchronization is a cornerstone of the cloud computing experience, even if you do access the file locally. For more, check out our roundup of the The Best Cloud Storage and File-Syncing Services for 2020.
Cloud Hardware
The primo example of a device that is completely cloud-centric is the Chromebook. These laptops have just enough local storage and power to run Chrome OS, which essentially turns the Google Chrome web browser into an operating system. With a Chromebook, almost everything you do is online: apps, media, and storage are all in the cloud. Because of that, they tend to be inexpensive and that's made them incredibly popular for education. The latest, made since 2017, will even run Android apps.
You can even try a ChromeBit, a smaller-than-a-candy-bar drive that turns any display with an HDMI port into a usable computer running Chrome OS. Asus still sells one.
What happens if you're somewhere without an internet connection and you need to access your data? This is one of the biggest complaints about Chrome OS, although its offline functionality has improved.
The Chromebook isn't the first product to try this approach. So-called "dumb terminals" that lack local storage and connect to a local server or mainframe go back decades. The first internet-only product attempts included the old NIC (New internet Computer), the Netpliance iOpener, and the disastrous 3Com Ergo Audrey. You could argue they all debuted well before their time—dial-up speeds of the 1990s had training wheels compared to the accelerated broadband internet connections of today.
That's why many would argue that cloud computing works at all: the connection to the internet is as fast as the connection to the hard drive. At least it is for some of us.
Arguments Against the Cloud
In a 2013 edition of his feature What if?, xkcd-cartoonist (and former NASA roboticist) Randall Monroe tried to answer the question of "When—if ever—will the bandwidth of the internet surpass that of FedEx?" The question was posed because no matter how great your broadband connection, it's still cheaper to send a package of hundreds of gigabytes of data via FedEx's "sneakernet" of planes and trucks than it is to try and send it over the internet. (The answer, Monroe concluded, is the year 2040.)
Cory Doctorow at boingboing took Monroe's answer as "an implicit critique of cloud computing." To him, the speed and cost of local storage easily outstrips using a wide-area network connection controlled by a telecom company (your ISP).
That's the rub. The ISPs, telcos, and media companies control your access. Putting all your faith in the cloud means you're also putting all your faith in continued, unfettered access. You might get it, but it'll cost you. The more bandwidth you use, the more it costs.
Maybe you trust those corporations. That's fine, but there are plenty of other arguments against going into the cloud whole hog. Consider the potential for crashes. When there are problems at a company like Amazon, which provides cloud infrastructure to big name companies like Netflix and Pinterest, it can take out all those services. And more. When Amazon's S3 service got mis-configured in 2017, it took out a hefty chunk of the entire internet across the board. The problems typically last for only hours, but that's not much consolation at the time.
To be honest, it doesn't matter. Cloud computing may be a little bit like the Wild West, where the rules are made up as you go, and you hope for the best, but it's here to stay. The money made by the cloud is immense, the ease of use speaks for itself.
TYPE OF CLOUD COMPUTING
Public cloud
Public clouds are owned and operated by a third-party cloud service providers, which deliver their computing resources, like servers and storage, over the Internet. Microsoft Azure is an example of a public cloud. With a public cloud, all hardware, software, and other supporting infrastructure is owned and managed by the cloud provider. You access these services and manage your account using a web browser. Learn more about the public cloud.
Private cloud
A private cloud refers to cloud computing resources used exclusively by a single business or organization. A private cloud can be physically located on the company’s on-site datacenter. Some companies also pay third-party service providers to host their private cloud. A private cloud is one in which the services and infrastructure are maintained on a private network. Learn more about the private cloud.
Hybrid cloud
Hybrid clouds combine public and private clouds, bound together by technology that allows data and applications to be shared between them. By allowing data and applications to move between private and public clouds, a hybrid cloud gives your business greater flexibility, more deployment options, and helps optimize your existing infrastructure, security, and compliance. Learn more about the hybrid cloud.
