Black Friday
An online shop is quiet on most days. On Black Friday it gets twenty times more visitors. If it owned all its computers, most of them would do nothing for the other 364 days.
So the shop uses the cloud. Cloud computing means using computers, storage and programs that belong to someone else, over the internet. When the sale ends, the shop gives the extra computers back.
Key words
| Word | What it means | Example |
|---|---|---|
| Cloud computing | Using computers, storage and programs that belong to someone else, over the internet. | Saving photos online |
| Public cloud | A cloud owned by a provider and shared by many customers. | A large company that rents out servers to many customers |
| Private cloud | A cloud used by one organisation only. | A bank's own data centre |
| Data centre | A building full of servers, storage and network equipment. | A large warehouse of servers |
| Elasticity | Adding or removing resources quickly as demand goes up and down. | More servers for a sale |
| Portability | Being able to move work and data from one place or provider to another. | Open your files on any device |
| Pay as you go | You pay only for what you use, for as long as you use it. | A bill for 10 hours of a server |
| Network | Computers joined together to share data. | The internet |
| Virtualisation | Making virtual versions of computers and their parts. | Many virtual computers on one real computer |
The cells students fill in are left blank in this preview.
Public or private cloud?
Have a go
Public or private cloud?
5 questionsYour answers are marked here and are not kept. A college account keeps every student’s marks.
Public and private cloud compared
| Public cloud | Private cloud | |
|---|---|---|
| Who owns it | A provider, shared by many customers | One organisation, or one rented for them alone |
| Cost | Low to start. You pay as you go. | High to start. You pay for the hardware and the staff. |
| Control | The provider decides many things | The organisation decides everything |
| Speed to grow | Very fast | Slower: you must buy more hardware |
| Good for | Start-ups, tests, busy and quiet periods | Strict rules, sensitive data, steady work |
The cells students fill in are left blank in this preview.
Extra: Real public cloud providers
Three big public cloud providers are Amazon Web Services (AWS), Microsoft Azure and Google Cloud. Each one has data centres in many countries. Many customers share them.
In the exam, say "a public cloud provider". You do not need the names.
Quick check
Have a go
Quick check
3 questionsYour answers are marked here and are not kept. A college account keeps every student’s marks.