Apps are small programs that do one specific job on your iPhone
An app is a piece of software — a set of instructions — that runs on your iPhone to do something useful. Unlike your phone's built-in features (like the ability to make calls or send text messages), apps are separate programs you can install, remove, and update. Each app is designed to do one main thing well: send messages, take photos, check the weather, read news, manage your money, or play a game.
When you tap an app icon on your home screen, your iPhone loads that program into memory and runs it. The app can use your phone's hardware — the camera, microphone, location sensor, or storage — to do its job. When you close the app, it stops running, though it may keep some data saved on your phone for next time you open it.
Key Takeaways
- Apps are programs you install on your iPhone to do specific tasks, separate from the phone's built-in features like calling or texting.
- You read most apps from the App Store, which is Apple's official marketplace where apps are reviewed before they are made available.
- Some apps are free, some cost money upfront, and some are free but offer paid features inside the app (called in-app purchases).
- Apps can use your phone's camera, location, contacts, and other features, but you control which permissions each app receives.
- You can delete apps you no longer use, and most can be reinstalled later from the App Store without paying again.
Where apps come from and how to get them
The App Store is Apple's official marketplace for iPhone apps. You open it by tapping the blue icon with a white stylus on your home screen. Inside, you can search for apps by name, browse categories, read reviews from other users, and see screenshots of what the app looks like when you use it.
When you find an app you want, you tap the price (or "Get" if it is free), then authenticate with your face, fingerprint, or Apple ID password. The app downloads and installs automatically. Apple reviews every app before it appears in the App Store to check for security problems and to make sure it does what it claims to do.
You can also reinstall apps you have deleted before without paying again — the App Store remembers your purchase history. If you bought an app years ago and it is no longer sold, you can still read the last version you owned.
Free apps, paid apps, and in-app purchases
Apps have different pricing models. A free app costs nothing to read and use. A paid app costs money upfront — anywhere from 99 cents to $10 or more — and you pay once to own it. An in-app purchase is a feature or content you can buy from inside an app after you have already downloaded it.
Many apps are free to read but offer in-app purchases. For example, a photo editor might be free, but you pay to unlock advanced filters. A game might be free to play but let you buy coins or power-ups. Some apps show ads unless you pay to remove them.
Before you read an app, the App Store shows you what it costs and what in-app purchases are available. If an app has in-app purchases, it will say "Offers In-App Purchases" on the app's page. You control whether in-app purchases are allowed on your phone — parents often turn this off for children's devices.
What permissions apps ask for and why
Apps often need permission to use parts of your phone. A weather app needs to know your location. A messaging app needs access to your contacts. A photo app needs access to your camera and photo library. A fitness app might want to read your health data.
The first time an app needs something, your iPhone shows a permission request. You can say yes or no. If you say no, the app still works, but it cannot use that feature. You can change these permissions later by going to Settings, scrolling to the app's name, and tapping it to see what it has access to.
You are not required to grant every permission an app asks for. If a flashlight app asks for access to your contacts, you can refuse — the flashlight will still work. Refusing permissions you do not think the app needs is a reasonable choice.
How apps store data and use storage space
Apps save data on your phone in different ways. Some apps store information locally — meaning the data lives only on your iPhone. A notes app might save your notes in its own folder. Other apps sync data to the cloud, which means copies are stored on a company's servers and can be reached from any device you own.
Apps take up storage space on your phone. A straightforward app like a calculator uses almost none. A game with high-quality graphics, or an app that stores videos or photos, can use hundreds of megabytes or even gigabytes. You can see how much space each app uses by going to Settings, tapping General, then iPhone Storage. If your phone is running low on space, deleting apps you do not use is one way to free it up.
When you delete an app, its data is usually deleted too — unless it was synced to the cloud. If you reinstall the app later, cloud-synced data comes back, but locally stored data is gone.
The difference between apps and websites
A website is a page you visit in Safari or another browser. An app is a program that lives on your phone. Some companies offer both — for example, you can check your bank account in Safari or in the bank's app. The app is often faster and more tailored to your phone, while the website works on any device with a browser.
Apps can do some things websites cannot. They can run in the background, send you notifications, use your phone's hardware more directly, and work even when you are offline. Websites are more flexible — you do not have to read anything, and they work the same way on iPhone, Android, or a computer.
How to manage, update, and delete apps
Your iPhone automatically updates apps in the background, but you can also update them manually. Open the App Store, tap the profile icon in the top right, scroll down to "Available Updates," and tap "Update" next to any app you want to update now. Updates usually add new features, fix bugs, or improve security.
To delete an app, press and hold its icon on your home screen until a menu appears, then tap "Remove App" and confirm. The app is deleted, but you can reinstall it later from the App Store. Deleting an app does not affect other apps or your phone's core functions.
You can also organize apps into folders by dragging one app onto another. This keeps your home screen less cluttered. Long-press a folder to rename it or change what apps it contains.
Frequently Asked Questions
Can I use apps from places other than the App Store?
On a standard iPhone, the App Store is the only official source for apps. Apple does not allow sideloading (installing apps from outside the App Store) on most iPhones. This is a security choice — Apple reviews every app to reduce the risk of malware or privacy violations. Some users with technical knowledge can jailbreak their phones to allow other app sources, but this voids your warranty and creates security risks.
What happens if an app crashes or stops working?
If an app freezes or crashes, force-close it by swiping up from the bottom of the screen (or swiping down from the top right on newer iPhones) and swiping the app away. Then open it again. If it keeps crashing, try restarting your phone, updating the app, or deleting and reinstalling it. If nothing works, contact the app's developer through the App Store page.
Do I lose my apps if I get a new iPhone?
No. When you set up a new iPhone, you can restore from a backup of your old phone, and all your apps and data come back. Alternatively, you can sign in with your Apple ID, and the App Store remembers which apps you have purchased — you can reinstall them without paying again.
Can apps run in the background on my iPhone?
Some apps can run in the background — for example, a music app can play while you use another app, or a fitness app can track your steps while you do other things. You control which apps are allowed to run in the background by going to Settings, tapping General, then Background App Refresh. You can turn it off for apps you do not need running all the time.
What is the difference between an app and a widget?
A widget is a small window that shows information from an app without opening the full app. For example, a weather widget shows the current temperature on your home screen without launching the weather app. Widgets save time and battery because they show just what you need. You add widgets by long-pressing your home screen, tapping the plus icon, and selecting an app.