An application is a program you run on your device to do a specific task
When someone says "application" or "app," they mean software designed to perform one job or a related set of jobs. A web browser is an application. A photo editor is an application. A calculator is an application. The difference between an application and your operating system (like Windows or macOS) is that the operating system runs your device itself, while an application runs on top of it to let you do something useful.
The word "application" comes from the idea of applying a tool to a problem. You apply a hammer to drive a nail. You apply a word processor to write a document. In tech, the term stuck around even as software became more complex, and now it covers everything from simple tools to massive programs with thousands of features.
You will hear "application" used three different ways depending on context: to mean any software program at all, to mean specifically programs you download and install (as opposed to websites you visit), or to mean mobile apps on phones and tablets. All three uses are correct, and context tells you which one someone means.
Key Takeaways
- An application is software built to do a specific task or set of related tasks on your device.
- Applications run on top of your operating system and need that system to function.
- Desktop applications you download and install are different from web applications you access through a browser, though both are called applications.
- Mobile apps on phones and tablets are applications designed for smaller screens and touch input.
- The word "application" is broad enough to cover everything from a simple calculator to complex programs like video editors or spreadsheets.
Desktop applications versus web applications
A desktop application is software you download and install on your computer. Microsoft Word, Adobe Photoshop, and Slack are desktop applications. When you install them, they take up space on your hard drive and run directly on your operating system. They usually work the same way whether you are online or offline, though some features may require an internet connection.
A web application is software that runs in your browser instead. Gmail, Google Docs, and Canva are web applications. You do not install them — you visit a website and use the program there. Web applications store your files on the company's servers (in the cloud) rather than on your device. They require an internet connection to work, but they take up almost no space on your computer.
The line between these two has blurred over time. Many desktop applications now sync with cloud storage. Many web applications let you work offline and sync when you reconnect. But the core difference remains: desktop applications live on your device, web applications live on someone else's server and you access them through your browser.
Mobile apps and how they differ from desktop software
A mobile app (or mobile application) is software built for phones and tablets. You download them from the App Store (on iPhones), Google Play (on Android phones), or similar stores. Mobile apps are designed for smaller screens and touch input instead of a keyboard and mouse. They often work offline or with limited internet, and they sync data when you reconnect.
Mobile apps are usually simpler and more focused than their desktop versions. The Instagram app on your phone does fewer things than the Instagram website on a computer, but it is faster and easier to use on a small screen. Some companies make both a desktop version and a mobile app of the same program — Spotify, for example, has a desktop application and a mobile app, and they work slightly differently.
Mobile apps also have stricter rules about what they can do. Apple and Google review apps before they go in their stores to check for security problems and rule violations. Desktop applications have fewer restrictions, which is why desktop software can sometimes do things mobile apps cannot.
How applications get installed and updated
Desktop applications usually come from a download link on a company website, or from a software store like the Microsoft Store or Steam. You download an installer file, run it, and it copies the application onto your computer. Some applications ask for permission to make changes to your system during installation — this is normal, though you should only install software from sources you trust.
Mobile apps come from the App Store or Google Play. You tap "Get" or "Install," and the store downloads and installs the app automatically. You do not see an installer file — the store handles it behind the scenes.
Updates work differently depending on the type. Desktop applications usually notify you when an update is available and ask if you want to install it now or later. Some let you turn on automatic updates. Mobile apps often update automatically in the background, though you can usually turn this off in your phone's settings. Web applications update on their own — you never have to do anything, which is why they are always the latest version.
Why the word "application" matters
Understanding what "application" means helps you make sense of tech conversations and instructions. If someone tells you to "download an application," you know they mean software you install on your device, not a website you visit. If they say "web application," you know it runs in your browser. If they say "mobile app," you know it is for your phone.
The term also matters for security and privacy. Desktop applications have direct access to your device and files, so you should only install them from trusted sources. Web applications run in your browser, which has built-in protections, but they store data on someone else's server. Mobile apps are reviewed before they go in the store, which adds a layer of safety. Knowing which type of application you are using helps you understand what permissions it needs and why.
Common confusion: applications versus programs versus software
In everyday use, "application," "program," and "software" mean almost the same thing. Technically, "software" is the broadest term — it includes everything from your operating system to device drivers to applications. A "program" is a piece of software that does something. An "application" is a program designed for end users to accomplish a task. But in normal conversation, people use these words interchangeably, and that is fine.
The only time the distinction matters is when someone is being precise about what they mean. If a tech support person says "this is a software issue," they might mean a problem with any piece of code on your device. If they say "this is an application issue," they usually mean the problem is with a specific program you are running, not with your operating system or drivers.
Frequently Asked Questions
Is a website the same as an application?
A website is a collection of pages you visit in your browser. An application is software that does something. A website can contain a web application (like Gmail), or it can just be pages of information (like a news site). So some websites are applications, but not all websites are.
Do I need to pay for applications?
Some applications are free, some cost money upfront, and some are free but charge for extra features. This is true for desktop apps, mobile apps, and web applications. Free does not mean unsafe — many popular applications are free. Paid does not mean better — it depends on what you need.
What happens if I uninstall an application?
For desktop applications, uninstalling removes the program from your computer and frees up the space it was using. Your files created in that application usually stay on your computer unless you delete them separately. For mobile apps, uninstalling removes the app and its data. For web applications, there is nothing to uninstall — you just stop visiting the website.
Can an application steal my information?
An application can only access information you give it permission to access. When you install a desktop application or mobile app, it asks for permissions (like access to your camera or contacts). You can usually see what permissions an app has and change them in your device settings. Web applications cannot access your files or camera without your permission, but they can see what you type into them.
Why do applications need updates?
Updates fix security problems, add new features, and improve how the application works. Security updates are especially important because they patch holes that hackers could use. It is a good idea to install updates when they become available, though you can usually wait until a convenient time.