An application is a program you run on your device that does a specific job
An application (or app) is software designed to perform a particular task or set of tasks on your computer, phone, or tablet. Unlike your device's operating system — which manages the hardware and lets everything run — an application does one thing or a few related things well. A weather app shows you forecasts. A calculator app does math. A word processor lets you write and format documents. Each one is built to solve a specific problem or meet a specific need.
Applications live on your device's storage and launch when you open them. They use your device's processing power, memory, and sometimes your internet connection to work. When you close an app, it stops running, though it stays stored on your device until you remove it. Most apps are designed to work with a specific operating system — iOS apps run on iPhones and iPads, Android apps run on most phones and tablets, and Windows or Mac apps run on computers.
Key Takeaways
- Applications are programs that perform specific tasks, separate from your device's operating system.
- Apps can be downloaded from official stores like the Apple App Store, Google Play Store, or Microsoft Store, or installed from a computer.
- Some apps are free, some cost money upfront, and some are free but show ads or offer paid features inside the app.
- Applications use your device's storage space, memory, and sometimes your internet connection to run.
- You can remove an app from your device at any time, though this deletes it unless you back it up elsewhere.
Where applications come from and how to get them
Most people download applications from official app stores built into their devices. On iPhones and iPads, that's the Apple App Store. On Android phones and tablets, it's Google Play Store. On Windows computers, it's the Microsoft Store. On Mac computers, it's the Mac App Store. Each store reviews apps before listing them, though the level of review varies.
You can also download applications directly from a company's website — many software makers let you download their programs this way. On Windows and Mac computers, you might also install applications from a disc or USB drive, though that's less common now. When you download an app, it installs itself on your device, taking up storage space. The amount varies widely: some apps use just a few megabytes, while others use several gigabytes.
How applications use your device's resources
When you open an app, it uses your device's processor (the chip that does calculations), its memory (RAM, which holds information while the app is running), and its storage (the permanent space where the app lives). If you run many apps at once, your device can slow down because it's dividing its processor and memory among them. Closing apps you're not using frees up that memory.
Many applications also use your internet connection to work — a weather app needs internet to fetch forecasts, a social media app needs it to load your feed, and a video streaming app needs it to download video. Some apps work without internet but have limited features. Others require internet to function at all. Your device's battery also drains faster when apps are running, especially if they're using the internet, your camera, or your location.
Different types of applications and how they're priced
Applications fall into several categories based on what they do. Productivity apps help you work — word processors, spreadsheets, note-taking tools. Communication apps let you message, email, or video call. Entertainment apps stream music, video, or games. Utility apps do single focused tasks like converting units or managing files. Social apps connect you to other people. Most devices come with some built-in apps, and you download others based on what you need.
Pricing varies widely. Some apps are completely free with no ads or paid features — the maker funds them another way or builds them as a public service. Some apps are free but show advertisements. Some apps are free but offer paid features inside the app (called in-app purchases) — you might play a game for free but pay to unlock levels or buy virtual items. Some apps cost money upfront — you pay once when you download, and then own it. Some apps use a subscription model — you pay monthly or yearly to keep using them.
Installing, updating, and removing applications
Installing an app is usually automatic — you find it in your device's app store, tap or click the download button, and it installs itself. On phones and tablets, this happens in the background. On computers, you might see an installation window that walks you through the process. Once installed, the app appears on your home screen or in your applications folder.
App makers regularly release updates that fix problems, add features, or improve security. Most devices can update apps automatically, though you can also update them manually through your app store. Removing an app is equally simple — on phones and tablets, you long-press the app icon and select delete or uninstall. On computers, you find the app in your applications folder or control panel and uninstall it. Removing an app frees up storage space, though any data the app stored on your device is usually deleted too (unless you've backed it up).
The difference between web applications and installed applications
Not all applications live on your device. Web applications run in your web browser and exist on a company's servers instead. Gmail, Google Docs, and Canva are web applications — you access them by visiting a website, and they work the same way on any device with a browser. Web apps don't take up storage space on your device, and they update automatically on the server side, so you always have the latest version.
Installed applications (sometimes called native apps or desktop apps) live on your device's storage and run locally. They typically work faster because they don't depend on your internet connection as much, and they can access your device's features more directly. The trade-off is that they take up storage space and need manual updates. Many companies now offer both — a web version you can use in a browser and an installed app for your phone or computer.
Security and permissions: what applications can access
When you install an app, it asks for permission to access certain features of your device — your camera, microphone, location, contacts, photos, or calendar. You can usually see what permissions an app is requesting before you install it, and you can change these permissions later in your device's settings. It's worth checking: a flashlight app doesn't need access to your contacts, and a weather app doesn't need your camera.
Apps can also be a security risk if they're malicious or poorly made. Official app stores review apps before listing them, which reduces but doesn't eliminate this risk. Downloading apps only from official stores, keeping your device's operating system updated, and being cautious about what permissions you grant all help protect your device. If an app behaves strangely, uses too much battery, or shows unexpected ads, you can remove it.
Frequently Asked Questions
What's the difference between an app and software?
App is short for application, so they're the same thing. Software is a broader term that includes applications, operating systems, and other programs. All apps are software, but not all software is an app.
Can I use the same app on my phone and computer?
Sometimes. Many companies make versions of their app for different devices — Microsoft Word exists for iPhone, Android, Windows, and Mac. But you typically download each version separately from the appropriate app store. A few apps use cloud sync to share your work across devices.
Why do apps need so many permissions?
Apps request permissions to access features they genuinely need to work. A photo editing app needs access to your photos. A maps app needs your location. But some apps request more permissions than they actually need, either out of habit or to collect data about you. You can deny permissions and the app will still work, though with reduced features.
Do I have to pay for apps?
No. Many useful apps are completely free. Some are free but show ads. Some offer a free version with limited features and a paid version with more. Others cost money upfront. You can find quality apps in every pricing model.
What happens to my data if I remove an app?
When you uninstall an app, any data it stored on your device is usually deleted too — your notes, photos, game progress, or settings. Some apps back up data to the cloud automatically, so you can recover it if you reinstall. Check an app's settings before removing it if you want to keep your data.