One app, three homes
You make a ticket app. Aisha has an iPhone. Ben has an Android phone. Sam uses a laptop.
The app must work for all three. But each one runs software in a different way. The place your software must run is its target platform.
You choose the target platform early, because it changes your design.
Key words
| Word | What it means | Example |
|---|---|---|
| Target platform | The kind of device and software your product must run on. | |
| Operating system | The main software that runs a device and its apps. | Windows, Android, iOS, Linux |
| File system | The way a device stores and names files and folders. | NTFS, ext4 |
| Server | A computer that gives data or services to other computers. | |
| Physical server | A real machine that you can touch. | |
| Virtual machine | A computer made by software. It runs inside a real computer. | |
| Infrastructure | The computers and storage that your software runs on, and the links between them. | |
| Language stack | The set of languages and tools used together to build a product. | JavaScript + Python + SQL |
| Native app | An app built for one kind of device and installed on it. | |
| Web app | An app that runs in a browser on any device. |
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Why the platform matters
Each platform has its own rules. A Windows program does not run on an iPhone. A phone has a small touch screen and a battery. A server has no screen at all.
If you learn the rules late, you must rebuild. So ask early: where will this run?
Quick check: platforms
Have a go
Quick check: platforms
3 questionsYour answers are marked here and are not kept. A college account keeps every student’s marks.
Five things to check
| Feature | The question | It can change your design |
|---|---|---|
| Operating system | Windows, macOS, Linux, Android or iOS? | Which languages, tools and app stores you can use |
| File system | How are files named and stored? | File name rules, size limits, whether upper and lower case differ |
| Server and infrastructure | A physical server, a virtual server or the cloud? | Cost, speed, how you grow, who looks after it |
| Language stack | Which languages and tools do the team and the platform support? | Hiring, training, libraries |
| Mobile or web | A phone app or a website, or both? | Screen size, touch, battery, offline use, updates |
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Physical and virtual servers
| Physical server | Virtual server | |
|---|---|---|
| What it is | A real machine in a room | A machine made by software, on a real one |
| Setup time | Days or weeks to buy and install | Minutes |
| Cost pattern | Pay a lot at the start | Pay as you use it |
| Control | Full control of the hardware | Less control of the hardware |
| Good for | Special hardware, strict rules about where data lives | Fast change and growth |
The cells students fill in are left blank in this preview.
Mobile or web?
A native app is made for one kind of phone. It can use the camera, GPS (it finds where you are) and notifications well. You must follow the app store rules. Each system needs its own version.
A web app runs in the browser. One version works on many devices. But it has less access to the phone, and it needs a connection for most jobs.
Scenarios: choose the platform
Have a go
Scenarios: choose the platform
4 questionsYour answers are marked here and are not kept. A college account keeps every student’s marks.