Apps are programs you download and install on your iPhone to do specific tasks
An app is a piece of software built to run on your iPhone and do one thing or a few related things well. When you open an app, you're running a program that lives on your phone — not just viewing a website. Apps can work even when you're offline, send you notifications, access your phone's camera or location, and store data directly on your device. The App Store is Apple's official marketplace where you find, download, and install apps on your iPhone.
Apps are different from websites. A website runs in your browser and lives on a company's server — you see it through Safari or another browser app. An app is installed on your phone itself. This means apps can be faster, work without internet, and use your phone's hardware in ways websites cannot. Some companies offer both: Instagram has a website you can visit, but the Instagram app is a separate program you install from the App Store.
Key Takeaways
- Apps are programs you install on your iPhone from the App Store, and they run directly on your phone rather than through a browser.
- Built-in apps like Mail, Calendar, and Camera come with your iPhone, while third-party apps like TikTok or Spotify you download yourself.
- Apps can access your camera, location, contacts, and photos only if you give them permission, which you control in Settings.
- Deleting an app removes it from your phone, but you can reinstall it later from the App Store without paying again if it was free.
Built-in apps that come with every iPhone
Your iPhone arrives with apps already installed that handle core tasks. Mail lets you read and send email. Calendar stores your schedule. Camera takes photos and videos. Photos organizes everything you've captured. Maps gives you directions. Stocks, Weather, Notes, Reminders, and Health are all built in. You cannot delete some of these — they're part of iOS, Apple's operating system — but you can hide them from your home screen if you don't use them.
Apple also includes Safari, which is the browser app for visiting websites. This is different from the apps themselves. Safari is the tool you use to view web pages; an app like Twitter is a program that shows you tweets in a format Twitter designed specifically for iPhone.
Third-party apps you download from the App Store
Third-party apps are programs made by other companies and individuals. You find them by opening the App Store app on your iPhone, searching for what you want, and tapping the cloud icon with a down arrow to download. Some are free. Some cost money, which you pay through your Apple ID. Once you've bought an app, you own the right to use it — you can reinstall it later without paying again.
Popular third-party apps include social media (Instagram, TikTok, X), messaging (WhatsApp, Telegram), streaming (Netflix, Spotify), banking (your bank's app), and productivity (Microsoft Word, Google Drive). Each one is a separate program made by a different company. When you download an app, you're trusting that company with access to parts of your phone — your location, your contacts, your photos — depending on what the app needs to work.
How apps access your phone's features and data
Apps can ask permission to use your camera, microphone, location, contacts, photos, and calendar. When you first open an app that needs one of these, iOS shows you a prompt asking whether to allow it. You can say yes, no, or "only while using the app." These permissions are not permanent — you can change them anytime in Settings.
To see what permissions you've given to each app, open Settings, scroll down to find the app's name, and tap it. You'll see toggles for Camera, Microphone, Location, Photos, Contacts, and other features. If an app has permission to your location, it can track where you are. If it has permission to your photos, it can see every photo on your phone. You control this. If an app asks for permission to something it doesn't need — like a flashlight app asking for your contacts — you can refuse.
Installing, updating, and removing apps
To install an app, open the App Store, search for it, and tap the cloud-with-arrow icon. The app downloads and installs automatically. On your home screen, you'll see a new icon you can tap to open it. If you've bought an app before, the icon shows a cloud instead of a price, and you can reinstall it free.
Apps update regularly with bug fixes and new features. You can set your iPhone to update apps automatically, or update them manually by opening the App Store, tapping your profile picture in the top right, scrolling down to "Available Updates," and tapping "Update" next to each app. To remove an app, press and hold its icon on your home screen, tap "Remove App," and choose "Delete App." This removes it from your phone, but you can reinstall it from the App Store later if you change your mind.
How apps store data and what happens to it
Apps store information on your phone — your messages in iMessage, your notes in Notes, your photos in Photos. Some apps also sync this data to the company's servers. WhatsApp stores your messages on your phone and their servers. Dropbox stores files you upload to their servers. Gmail stores your emails on Google's servers. When you delete an app, the data it stored on your phone is usually deleted too, but data on the company's servers may remain.
If you sign into an app with your Apple ID, iCloud account, or a company account, that company can see what you do in the app. If you use an app without signing in, it may still collect information about how you use it — what you tap, how long you stay, what you search for. You can see what data apps collect in the App Store: search for the app, scroll down to "Privacy," and you'll see a summary of what information it requests.
The difference between apps and websites
A website is a collection of pages you view through a browser. An app is a program installed on your phone. Websites work on any device with a browser — your phone, tablet, or computer. Apps are built for a specific device: an iPhone app won't work on Android, and vice versa. Apps are usually faster because they're optimized for your phone's hardware. Websites are more flexible because they work everywhere.
Some companies make both. You can visit Twitter.com in Safari, or download the Twitter app. You can check your bank's website in Safari, or use their app. The app version is often faster and sends you notifications, while the website version works on any device. Neither is inherently better — it depends on what you're doing and what you prefer.
Frequently Asked Questions
Can I use my iPhone without downloading any apps?
Yes. You can use Safari to visit websites, send email through the Mail app, and do most things through your browser. You don't have to download any third-party apps. Many people use only the built-in apps and Safari. Apps are optional — they're just another way to do things, often faster or with more features.
What happens to my data if I delete an app?
Data stored on your phone is usually deleted when you remove the app. Data the app stored on the company's servers — like your Gmail messages or Dropbox files — stays there. If you reinstall the app later and sign back in, you'll see that data again. Some apps let you export your data before you delete them.
Do I have to pay for apps?
No. Many apps are free, including Instagram, TikTok, Spotify, and Gmail. Some apps cost money upfront — you pay once and own it. Some are free but charge for extra features inside the app. You control what you spend through your Apple ID payment method, and you can turn off in-app purchases in Settings if you want to prevent accidental charges.
Can apps see everything on my phone?
No. Apps can only access what you give them permission to use. When an app asks for permission to your camera, location, or photos, you can say no. If you refuse, the app cannot access those things. You can change permissions anytime in Settings. An app cannot see your other apps, your passwords, or data from other apps unless you explicitly share it.
What's the difference between updating an app and updating iOS?
iOS is Apple's operating system — the software that runs your entire iPhone. Apps are individual programs that run on top of iOS. You update iOS through Settings > General > Software Update. You update individual apps through the App Store. Both add bug fixes and features, but they're separate updates for different things.