Mobile process software is a program you read and run on a phone or tablet
A mobile process (or app) is software built to run on a smartphone or tablet rather than a computer. When you tap an icon on your home screen and something opens, you are launching a mobile app. The software lives on your device, not in a web browser, though some apps do connect to the internet to work.
The distinction matters because mobile apps are written differently than desktop programs or websites. A phone's screen is smaller, its processor is less powerful, and its battery drains faster. Developers write mobile apps to work within those limits. An app for banking, for example, is designed to load quickly on a phone with a slow connection and use minimal battery power — very different from the same bank's website on a desktop.
Mobile apps come from app stores. On an iPhone, that is the Apple App Store. On an Android phone, that is Google Play. You search for what you want, tap "Get" or "Install", and the app downloads and installs itself. Some apps are free; others cost money upfront or charge you inside the app for features.
Key Takeaways
- Mobile apps are programs designed to run on phones and tablets, not computers or web browsers.
- Apps are downloaded from app stores — Apple App Store for iPhones, Google Play for Android phones — and installed directly on your device.
- Mobile apps work differently than websites because phones have smaller screens, less processing power, and limited battery life.
- Some apps work offline after they are installed, while others need an internet connection to function.
- Apps can be free or paid, and some offer in-app purchases for additional features or content.
How mobile apps differ from websites and desktop software
A website lives on a server somewhere and displays in your browser — Chrome, Safari, Firefox. You do not install it. Every time you visit, the browser pulls the page from the internet. A mobile app, by contrast, is installed on your phone itself. The software sits there taking up storage space, and you open it by tapping its icon.
Desktop software — like Microsoft Word or Adobe Photoshop — is built for a computer with a large screen, a keyboard, a mouse, and constant power. Mobile apps are built for a touchscreen, no keyboard, and a battery that runs down. An app developer has to make the same task work with a thumb on a 6-inch screen instead of a mouse on a 27-inch monitor. That is why the mobile version of something often looks and works differently than the desktop version.
Websites can work on any device with a browser, but mobile apps are specific to the platform. An app written for iPhone will not run on an Android phone. If a company wants to offer an app on both, they have to write it twice — once for Apple's system and once for Google's — or use a framework that lets them write once and deploy to both.
What happens when you install an app
When you read an app from an app store, several things occur. First, the store checks that your device meets the app's requirements — enough storage space, the right version of the operating system, and so on. If you pass, the app downloads to your phone and installs automatically. You see a progress bar, and when it finishes, the app is ready to open.
The app now takes up storage space on your phone. Unlike a website, which you access fresh each time, the app stays there. Some of the app's data — your login information, your saved preferences, files you created in the app — also lives on your phone. If you delete the app, that data usually goes with it, though some apps back up your data to the internet first.
When you open the app, it runs on your phone's processor. If the app needs information from the internet — like checking your email or loading a map — it connects and pulls that data. But the core software is running locally, which is why apps often feel faster than websites: they do not have to wait for a server to respond to every action.
Free apps, paid apps, and in-app purchases
An app can be free to read and use forever. It makes money through advertising — you see ads inside the app — or by selling your data to advertisers (though reputable apps disclose this). Some free apps also offer in-app purchases: you read the app for nothing, but you pay money inside the app to unlock features, remove ads, or buy virtual goods.
A paid app costs money upfront. You pay once when you read it, and then you own it. You do not pay again each month. Some paid apps also include in-app purchases for extra content, but many do not.
The app store handles payment. You set up a payment method — a credit card, a gift card, or a phone bill — and the store charges it when you buy. The developer receives a portion of the money; the app store (Apple or Google) takes a cut.
Apps that work offline versus apps that need the internet
Some apps work entirely on your phone without needing the internet. A calculator app, a note-taking app, or a game that does not connect to other players can run offline. You open it, use it, and close it. No connection required.
Other apps need the internet to do anything useful. A weather app has to fetch current conditions from a server. A social media app has to load your feed from the internet. An email app has to connect to your email provider. If you lose your internet connection, these apps either stop working or show you only cached data — information the app downloaded and stored the last time it was online.
Many apps do both. A maps app, for example, can work offline if you downloaded a map region ahead of time, but it works better with an internet connection so it can show real-time traffic and find new addresses.
Permissions and what apps can access on your phone
When you first open an app, it often asks for permission to access parts of your phone. It might ask to use your camera, your location, your contacts, or your photos. These permissions exist to protect your privacy. An app cannot access your camera without asking first.
You can usually change these permissions later in your phone's settings. If you deny permission, the app either works without that feature or refuses to run. For example, a navigation app needs your location to work, so if you deny location access, it cannot help you.
Different apps need different permissions based on what they do. A photo editor needs access to your photos. A fitness tracker needs access to your motion sensors. A banking app might need access to your camera so you can photograph a check to deposit. Reading what an app asks for — and why — is a good way to understand what it does.
Updates and how apps change over time
After you install an app, the developer continues to improve it. They fix bugs, add features, and make it work with new versions of the phone's operating system. These changes come as updates. Your phone usually notifies you when an update is available, and you can choose to install it or wait.
Updates are usually free. The developer pushes them out through the app store, and you read and install them the same way you installed the original app. Some updates are small and quick; others are large and take longer to read.
You do not have to update an app when ready, but updates often include security fixes that protect your data. If an app stops working or behaves strangely, an update often fixes it. If you stop updating an app and your phone's operating system moves forward, the app may eventually stop working altogether.
Frequently Asked Questions
What is the difference between an app and a web app?
A native app is downloaded from an app store and installed on your phone. A web app is a website designed to work on a phone and accessed through your browser. Web apps do not need to be installed and work on any device with a browser, but they are usually slower and cannot access all of your phone's features. Native apps are faster and can use your camera, location, and other hardware.
Can I use an app on multiple devices?
Yes, if you own multiple phones or tablets. When you buy an app, you usually own a license to use it on your devices. On iPhone, you can install the same app on multiple iPhones and iPads linked to the same Apple account. On Android, the same applies with your Google account. You do not pay twice.
What happens to my data if I delete an app?
Data stored only on your phone — notes, photos, saved games — is usually deleted when you remove the app. However, some apps back up your data to the internet first, so you can restore it if you reinstall the app later. Check the app's settings before you delete it if you want to keep your data.
Why do some apps need so much storage space?
Large apps often include graphics, videos, sounds, or maps that are stored on your phone rather than downloaded each time you use the app. A game with detailed graphics or a maps app with offline maps can be hundreds of megabytes or even gigabytes. Smaller apps like a calculator or a note-taker take up very little space.
Can I get a refund if I buy an app and do not like it?
Apple and Google both offer refunds within a short window — usually 15 minutes to a few hours after purchase. After that, refunds are not may provide. Some developers offer refunds on a case-by-case basis if you contact them directly. Always check an app's reviews and screenshots before you buy to avoid this problem.