What Is an App? The Program That Lives on Your Device
An app is one program, installed on your device, built to do one job well. A website you visit. An app you keep.
The whole idea, in one diagram
You download it once and it stays on your device, even without internet.
It has to ask permission before it can use your camera, your microphone or your location.
If an app is free, something else is usually paying for it. That is worth knowing.
What problem did it solve?
Getting a program meant going to a shop, buying a cardboard box with a disc inside, and installing it. If it had a mistake in it, that mistake stayed until you bought the next version. Small makers could not get onto shop shelves at all.
A shop built into the device itself, where any maker can publish, anyone can download in seconds, and the program can update itself afterwards.
Software went from something a few big companies sold in boxes to something millions of people make, including one person working alone. It also means every app you own is quietly changing all the time.
How it started
- 1970s to 1990s
Software in a box
👤 Software companies and computer shops
Programs came on floppy discs and later CDs, in cardboard boxes with printed manuals, bought from a shop.
Why it mattered: Shelf space decided what existed. If a shop would not stock your program, almost nobody could ever find it.
- 1990s to 2000s
Downloading instead of driving
👤 The early web
You could download a program straight from the internet, which cut out the shop and the disc.
Why it mattered: Cheaper and faster, and much riskier. There was no one checking whether what you downloaded was safe.
- 1994 to 2007
The first phone programs
👤 IBM Simon, then Nokia, Palm and BlackBerry
Early smart devices could run small programs, but installing them was awkward and there was no single place to find them.
Why it mattered: The idea worked. What was missing was a shop, a payment system and a way for makers to reach people.
- 2008
The app store arrives
👤 Apple in July 2008, with Android's store the same year
A shop built into the phone. Anyone could publish, users could install with one tap, and payment was handled for them.
Why it mattered: This is the moment. A teenager in a bedroom could now reach millions of people, which had simply never been possible before.
- 2009 onwards
Free apps, and the real price
👤 The whole industry
Most apps became free to install, making money instead through adverts, through paid extras inside the app, or by collecting information about you.
Why it mattered: Free removed the barrier and hid the cost. Understanding how an app makes money is now part of understanding whether to trust it.
- 2012 onwards
Apps have to ask
👤 Phone makers, pushed by users and by law
Instead of an app quietly using your camera, contacts or location, the phone began asking you first, and letting you say no.
Why it mattered: It moved a little power back to you. A torch app that wants your contacts is telling you something, and now you get to hear it.
Who made it happen
Steve Jobs
1955 to 2011 · USA
Led the launch of the phone app store in 2008, which turned software into something anyone could publish and anyone could install in one tap.
Andy Rubin
born 1963 · USA
Co-founded Android, the phone system now used by most of the world, with its own open app store.
Frank Canova
1994 · USA
Led the IBM Simon team, the first phone that could run small programs like a calendar and a notepad.
Markus Persson
born 1979 · Sweden
Made Minecraft largely on his own, a clear example of one person reaching millions once shops stopped being the gatekeeper.
Dong Nguyen
born 1985 · Vietnam
Built a hugely popular game alone in a few days, then removed it because he felt people were playing too much.
What happens from tapping install to tapping open
- 1
You find it in the store
The store is itself an app. It lists programs that the store owner has checked, at least to some degree, for obvious dangers.
- 2
It downloads and installs
The program file is fetched over the internet and unpacked into storage on your device. This is the only step that truly needs a connection.
- 3
It asks for permissions
Before it can use your camera, microphone, location, contacts or photos, it has to ask. You can say no, and a well-made app should still work for its main job.
- 4
It lives on your device
The app is now yours to open whenever you like. Many apps work with no internet at all, because everything they need is already there.
- 5
It updates itself
The maker can send fixes and changes after you have installed it. This is good for security, and it means the app you have today is not quite the one you installed.
Each invention solved the last one's problem
Software in a box
- Problem before
- You had to travel to a shop, pay a lot, and hope the shop stocked what you wanted.
- What it solved
- Programs became something you could actually buy and own at home.
- Impact
- Shelf space decided what existed. Small makers had almost no way to reach anyone.
Downloads from the web
- Problem before
- Boxes and discs were slow, expensive and limited to what shops chose to sell.
- What it solved
- You could get a program from the maker directly, in minutes.
- Impact
- Much cheaper and much riskier, because nobody was checking what you were downloading.
The app store
- Problem before
- Downloads were risky, hard to find and awkward to pay for.
- What it solved
- One trusted place, one tap to install, payment handled, and some checking of what gets published.
- Impact
- One person alone can now reach millions. It also means one company decides what is allowed on the device you own.
Free apps
- Problem before
- Paying up front stopped most people from ever trying an app.
- What it solved
- Install for nothing, and pay later through adverts, extras inside the app, or your information.
- Impact
- Far more people use far more apps. The cost did not disappear, it just became harder to see.
A website you visit and a fresh copy arrives each time. An app you install and it stays, which is why an app can work with no internet and why it has to ask permission before using your camera.
Open the settings on a phone and find the permissions list for two or three apps. Ask yourself, for each one, whether the app really needs that to do its job. A torch that wants your contacts, or a simple game that wants your location, is worth a conversation with a grown-up.
Quiz: how much did you remember?
Quiz time!
10 questions, picked at random from 30. No sign-in and no score is kept. Play as many times as you like, the questions change every time.
Questions about apps
What is an app in simple words?
An app is a program you install on a phone, tablet or computer to do a particular job: play a game, send a message, learn maths, take a photo. Once installed it lives on your device.
What is the difference between an app and a website?
You install an app once and it stays on your device, so it can often work without internet. A website is fetched fresh from a server every time you visit, and it needs a connection each time.
Why do apps ask for permission?
Because your camera, microphone, location, photos and contacts are private. Your phone makes apps ask first so that you can say no. A well-made app should still do its main job if you refuse.
How do free apps make money?
Usually one of three ways: showing you adverts, selling extras inside the app, or collecting information about you to sell to advertisers. If you cannot see how an app makes money, that is worth asking about.
Are apps from the app store always safe?
Safer, not guaranteed. The store does some checking, which is far better than downloading from anywhere. Bad apps still slip through, so it is always worth reading reviews and checking with a grown-up before installing.
Why do apps need updating so often?
To fix mistakes, to close security holes that criminals could use, and sometimes to add features. Updates are one of the simplest and most important ways to stay safe.
What was the first app store?
Apple opened its phone app store in July 2008, with Android's arriving the same year. Before that there was no single trusted place to find and pay for phone programs.
Can an app work without the internet?
Many can. If everything the app needs is already stored on the device, it works offline. Apps that show new messages, new videos or live scores need a connection because the information lives elsewhere.
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