Explaining the Cloud for Beginners
The cloud is the future of technology and the future of computing. In this article we'll talk about what is the cloud and what does it do? This article is written in a way so it's easy to understand.
The Beginning
The cloud, not the clouds in the sky, but the physical cloud that powers companies such as Google, Meta, Netflix, Apple, and more.
This is the cloud that everyone talks about. While it doesn’t look like a cloud, it is. More importantly, this is a data center. A data center is a giant warehouse-sized building that contains a lot of computers.
It can range from thousands to ten thousand to hundreds of thousands. A lot of computers!
This computer is built to fit in a data center. They slide into a rack as a way to keep computers together.
In general, the cloud is a big building that just has lots of computers inside.
You can rent computers in the cloud, as the cloud sells computers as services. But before we talk about that, let’s find out why it’s called the cloud in the first place.
Why Cloud?
This is basically what the cloud looks like. It is “thought the term cloud comes from the symbol used to represent a network when drawing flowcharts and diagrams”.
Lets say that you want to draw a computer network, but do you want to draw all the computers connected by wires? I’m going to assume NO because it would be a pain to draw all those computers, so instead of drawing all those computers, lets just draw something simple so we ended up with a cloud.
No one knows why we have chosen a cloud, but in the end, it was a great choice. Clouds are easy to draw and they can have any shape like networks. Clouds are made up of millions of tiny water droplets like how networks are made up of many pieces of equipment. So it makes sense to have a cloud represent a network.
Network
A network is what connects things together.
WiFi network connects computers to the internet. The cellular network connects phones together. The social network connects people together. The network is connecting all the devices that make up the internet.
Data centers are just another network. All those computers connect with each other and are made accessible over another network, the internet.
When you hear cloud, it means a network of computers accessed over the internet that also provides services. You never touch them or see them in real life because data centers are heavily guarded, so unless you’re a technician at one of these databases, it’s unlikely you will ever see them.
How cloud works
You’ve probably used the cloud before and just never realized it. If you use a credit card then you’re using the cloud. Pay bills online, you’re using the cloud.
Money is just a number. Your bank balance is just a number on a computer. Computers always know your bank balances unless there is a bug that causes the computer to display your bank balance wrong.
All numbers are stored and updated in the bank’s cloud. Your money is stored as numbers on the bank’s computers, which are in their cloud. When you buy something, a computer in your bank’s cloud takes the money out and adds it to the seller’s account.
There are two kinds of clouds: Cloud Providers and Cloud Services
Cloud services are those that offer services. Like how banks offered services on their cloud or how Apple’s iCloud keeps all your iOS devices in sync.
Cloud providers own those databases. It lets customers rent their computers to build services. A well-known cloud provider is Amazon Web Services (AWS). AWS is used by thousands of different companies to help with their services. Amazon rents their computers out as a service. You would pay Amazon money to use their service.
What is service
A service is a job that you hire someone else to do for you. We use services all the time. If your car breaks down, you hire a mechanic. If you want your car washed, you would take it to a car wash. Services are stuff you get in exchange for money.
What does a cloud service do?
There are a lot of services. The most common service is file sharing and storage. Some examples include exchanging messages, reading ebooks, sending and receiving emails, online accounting, and more.
A cloud is a separate place
The cloud is in a remote place. It is not on your phone and it is not on any device you use. It runs on computers in a data center. You can access the cloud through a program as the program knows how to talk with the cloud. The cloud never sleeps. It is always there, so even if you have lost your phone, and you have gotten a new one, all your messages would be there if you sign in to your iCloud.
What is stuff
Stuff is just data to a computer. You probably have a lot of stuff like photos, music, movies, text messages, etc. What we call all of this is data. Data is a record of stuff. You can think of data like ingredients in a recipe. Each ingredient is a piece of data and then you whip the data up to create a meal.
Storing in the cloud
You can think of the cloud as a storage unit where all your data is stored. A hard drive is what stores and provide access to a large amount of data.
Your stuff is stored in a real, physical piece of equipment that is also in a data center. You can think of all your data being stored on a hard drive.
What is an app
An app is a series of instructions that tell a computer what to do. It is what makes our devices useful. Apps contain a lot of instructions, they can be broken down into a lot more instructions. Creating instructions to do something is called programming. The text of the written instructions is called a program. The thing that understands and can interpret the program is a computer.
The Internet
The internet is sending data from one computer to another computer. Highways are basically like the internet; cars go from one place to another just like how data from one computer goes to another computer. In short, computers are basically talking to each other. The internet isn’t made up of concrete, but wires and cables that are strung across the planet. Electrical signals carry data from one place to another.
The lines in the image above represent wires and cables that form a network. Data is sent from your phone, from the internet, follows a route across the network to get to the cloud service, and then back to your device.
Giant cables run along the ocean floor, carrying data from one continent to another
What are datacenter
A datacenter is housing for computer systems and a bunch of equipment like storage. Cloud providers are the one that owns data centers and are the ones that built them. They can cost several billion dollars to build. Datacenters are located everywhere in every part of the world. The bigger the cloud provider is, the more data center it will have. The reason why there are data centers everywhere is all because of speed. The closer the data center is to you the faster computers in the data center can connect with you over the internet. That is why cloud providers build data centers near large populations.
A fast internet connection is what we want. Nobody wants slow internet that takes 10 minutes to load a website.
Amazon Data Centers
Microsoft Data Centers
Cloud Computing
Infrastructure as a service (IaaS) is something you’ll hear often also PaaS (platform as a service), and SaaS (software as a service).
Databases are always being repaired. Things break from time to time and need to be replaced. There is also the need for more computers, hard drives, and more networking devices. Keeping a data center up and running 24/7 is a lot of work.
In the cloud, services take care of all the infrastructure for you which is known as IaaS. Renting computers, storage and managing infrastructure is the kind of service the cloud offers.
PaaS on the other hand helps developers speed up development by doing work for them. Developers build and deploy their applications.
SaaS is when customers use a software product, not a service used in building other products. A great example of SaaS is Microsoft Office 365. You can use Office over the internet as a service, you don’t have to maintain it, upgrade it, or do anything with it other than use it. That is SaaS, software rented and used over the internet.
Both IaaS and PaaS are services used by developers to build products. No customers would ever use them, they are for developers.
Virtual Machines
When you rent a server in the cloud, you don’t rent the whole thing, you just rent part of it. Virtual Machine allows many programs to run on one computer at the same time.
This is a good picture of the structure of a virtual machine.
KVM stands for Kernel-based virtual machine. It’s software that runs on a bare-metal machine to virtualize it. Bare-metal means you’re directly using the computer’s hardware. The desktop you use at home or at work is a bare-metal computer.
At the lowest level is hardware like hard disks and CPUs. Above the hardware is the operating system that provides controlled access to hardware. Every computer runs on an operating system. It manages everything on the computer. Windows, Mac OS, iOS, or Linux are operating systems. Then above the operating system is KVM which virtualized the OS and the hardware so the application above will have complete access to its own computers.
A virtual machine pretends to be a computer, but it isn’t. It’s almost like a small slice of a computer, but programs don’t notice the difference between bare-metal and virtual machines. A program just thinks that it is running on a real computer.
Serverless
Instead of running a complete application in a VM, you upload a function into a serverless service and it takes care of everything. Serverless is cheaper and simpler which is good for developers. At the same time, it increases server utilization which results in higher profit for cloud providers.
AWS Lambda is the most popular.
Private and Public Cloud
AWS is a public cloud. Anyone can use them, but if you want a private cloud then you would have to build your own cloud in your own data centers.
The benefit of a private cloud is that you would have complete and total control of it, sensitive data would be much safer in private than in public, using special hardware that may not be available in the public cloud, and more.
There aren’t many private clouds because it is really hard to build a cloud, so in general choose a public cloud when possible.
Advantages and Disadvantages of the Cloud
Advantage:
Cloud storage is safe
Cloud storage is infinite
The cloud is available from any device
Cloud storage is permanent
The cloud is secure most of the time
Subscription-based cloud services are a better business model
Cloud apps have more powerful features
Disadvantage:
Cloud services close down
Cloud storage can be expensive
The cloud can be slow
The cloud can be unavailable
The government can get your data
Free services might sell your data
Companies using your data for dollars (selling your data to others)
If it’s free then beware because companies have to make money somehow to keep it running, so they might sell your data, which could be a violation of your privacy.
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