Applications are programs that do specific tasks on your phone, computer, or tablet
An application (or "app") is software designed to perform a particular job on your device. Unlike your operating system — which manages the whole device — an application does one thing or a set of related things. A weather app shows you forecasts. A banking app lets you check your balance. A photo editor lets you crop and filter pictures. Each one is built to solve a specific problem or let you do a specific activity.
Applications live on your device and run when you open them. Some are built into your device when you buy it (like the Camera app on an iPhone or the Calculator on Windows). Others you download and install yourself from a store — the Apple App Store on iPhones, Google Play on Android phones, or the Microsoft Store on Windows computers. Once installed, they take up storage space on your device and can be opened whenever you want.
Key Takeaways
- Applications are programs that perform specific tasks, separate from your device's operating system.
- You can download applications from official stores like the Apple App Store, Google Play, or Microsoft Store, or they may come pre-installed on your device.
- Applications require permissions to access parts of your device — like your camera, location, or contacts — and you control what you allow.
- Uninstalling an application removes it from your device and frees up storage space, though some built-in apps cannot be removed.
- Applications update regularly to fix problems, add features, and patch security issues, and you can usually choose whether to update automatically or manually.
How applications ask for permission to use your device's features
When you first open an application, it often asks for permissions — access to parts of your device it needs to work. A maps app needs to know your location. A messaging app needs access to your contacts. A video call app needs your camera and microphone. These requests appear as pop-up windows that let you say yes or no.
You are in control of these permissions. If an app asks for access to your location and you tap "Don't Allow," the app cannot use your location data — though it may not work as well, or at all. You can also change permissions later. On an iPhone, go to Settings, scroll to the app name, and tap it to see what permissions it has. On Android, do the same in Settings under Apps. On Windows, go to Settings, then Privacy & Security, and select the feature (like Camera or Microphone) to see which apps have access.
Some permissions make sense for what an app does. A camera app obviously needs camera access. Others are worth questioning. A flashlight app does not need to know your contacts or location. If an app asks for permissions that seem unrelated to what it does, you can refuse them or delete the app.
Where applications come from and how to install them safely
The safest place to download applications is an official store run by your device's maker. On iPhones and iPads, that is the Apple App Store. On Android phones, it is Google Play (though some phones also have Samsung Galaxy Store or other options). On Windows computers, it is the Microsoft Store. These stores check applications before they appear, though no check is perfect.
When you find an app you want, you tap or click the download button. The app downloads and installs automatically. You may be asked to sign in with your account (Apple ID, Google account, or Microsoft account) to confirm the purchase — even if the app is free. Once installed, the app appears on your home screen or in your app menu.
You can also download applications from a developer's website directly, but this is riskier because there is no middleman checking the code. Stick to official stores unless you have a specific reason to download from elsewhere. Never download an application from a link in an email or text message, even if it looks like it came from a company you trust — scammers fake those messages to trick you into installing malware.
How to update applications and why updates matter
Applications update regularly. Updates fix bugs (problems that make the app crash or behave strangely), add new features, and patch security vulnerabilities — holes in the code that hackers could exploit. You will see notifications telling you updates are available, or you can check manually in your app store.
On most devices, you can set applications to update automatically in the background, so you do not have to think about it. On an iPhone, open the App Store, tap your profile picture in the top right, scroll down, and turn on "Automatic Updates." On Android, open Google Play, tap your profile icon, go to Settings, then Network Preferences, and turn on "Auto-update apps." On Windows, the Microsoft Store updates apps automatically by default.
You can also update manually if you prefer. Open your app store, find the Updates section, and tap Update next to any app that has a newer version available. Manual updates give you control over when your device uses data and processing power, but automatic updates are simpler and keep you safer because security patches happen without you having to remember.
Uninstalling applications and freeing up storage space
If you no longer use an application, you can remove it to free up storage space on your device. On an iPhone, press and hold the app icon on your home screen, tap Remove App, then tap Delete App. On Android, press and hold the app icon, tap Uninstall, then confirm. On Windows, right-click the app in your Start menu or app list, select Uninstall, and follow the prompts.
Some applications come pre-installed on your device and cannot be uninstalled — you can only disable them so they do not appear in your app menu. On iPhones, you can remove most built-in apps (like Stocks or Reminders) by holding and deleting them, though a few like Settings cannot be removed. On Android, some built-in apps can be uninstalled and others can only be disabled; try uninstalling and the system will tell you if it is not allowed.
Uninstalling an app does not always delete the data it stored. Some apps save files or settings in your device's storage even after you remove them. If you want to fully clean up, check your device's storage settings. On iPhone, go to Settings, tap General, then iPhone Storage to see what is taking up space. On Android, go to Settings, tap Storage, then Manage Storage. You can delete leftover files manually if you want a complete removal.
The difference between web applications and installed applications
Not all applications live on your device. Web applications run in your web browser — like Gmail, Google Docs, or Canva. You do not download or install them; you just visit the website and log in. They work on any device with a browser, and they update automatically on the server side, so you always have the latest version.
Installed applications (sometimes called "native" or "desktop" apps) live on your device and often work faster because they do not have to send data back and forth to a server. They can also access your device's features more directly — like your camera, location, or files. The trade-off is that they take up storage space and you have to update them yourself.
Many companies offer both. You can use Gmail in your browser or download the Gmail app on your phone. You can edit documents in Google Docs online or download Google's office suite to your computer. Choose whichever fits your workflow — web apps are better if you switch devices often, and installed apps are better if you want speed or need to work offline.
How applications use your data and what you can control
Applications collect data to work and to improve themselves. A fitness app tracks your steps and heart rate. A shopping app remembers your search history and preferences. A social media app stores your posts and messages. Some of this data stays on your device; some is sent to the company's servers.
You can see what data an app collects by reading its privacy policy — a legal document that explains what information it gathers and how it uses it. Privacy policies are often long and written in legal language, but the key sections usually explain what data is collected, whether it is shared with third parties, and how long it is kept. Look for these sections before you download an app, especially if it asks for sensitive permissions like location or contacts.
You can also limit what data apps can access through your device's privacy settings. On iPhone, go to Settings and scroll through the list of apps to see what permissions each one has. On Android, do the same in Settings under Apps. You can turn off location, camera, microphone, contacts, photos, and other features on a per-app basis. Turning off a permission may make the app less useful, but it gives you control over your privacy.
Frequently Asked Questions
What is the difference between an app and a program?
The terms are often used interchangeably, but "program" is the older, broader term for any software that does a task. "App" is shorter and usually refers to applications on phones and tablets, though it is now used for computer software too. A program on your computer and an app on your phone do the same thing — they are just different words for it.
Can I use the same application on my phone and computer?
Sometimes. Many companies make versions of their app for different devices — like Microsoft Office for both Windows and iPad. But not all apps are available on all platforms. Check the app store for your device to see if the app you want exists there. Web applications work on any device with a browser, so those are the most flexible.
Why does an app need permission to access my contacts or photos?
An app needs these permissions to do its job. A messaging app needs your contacts to let you pick who to message. A photo editor needs access to your photos to let you edit them. A social media app needs your camera to let you take pictures. You can refuse any permission, but the app may not work as intended if you do.
What happens to my data if I uninstall an app?
Data stored on your device (like photos you edited in a photo app) usually stays on your device even after you uninstall the app. Data stored on the company's servers (like your email in Gmail) stays there too — uninstalling the app does not delete your account. If you want to permanently delete your account and all its data, you usually have to do that through the company's website or settings.
Is it safe to download applications from third-party websites?
It is riskier than downloading from official stores. Official stores check applications before they appear, though no check is perfect. Third-party websites do not have the same oversight, so malware or fake versions of popular apps can slip through. Stick to the Apple App Store, Google Play, or Microsoft Store unless you have a specific reason to download from elsewhere and you trust the source.