Application software is a program you run on your device to do a specific task

Application software is any program designed to help you accomplish something — write a document, edit a photo, manage your calendar, play a game, or video call a friend. It runs on your computer, phone, or tablet and does one job or a set of related jobs. The operating system (Windows, macOS, iOS, Android) is what makes your device work; application software is what you use the device for.

The distinction matters because it shapes what you can do and where you can get it. Application software depends on the operating system underneath it — a program written for Windows will not run on a Mac without modification, and an iPhone app will not work on an Android phone. You download and install applications separately from the operating system, and you can add, remove, or replace them without affecting how your device runs.

Most application software falls into a few broad categories based on what it does and where it lives. Understanding these categories helps you find the right tool for what you need and know where to look for it.

Key Takeaways

  • Application software is any program you run to do a specific task, separate from the operating system that runs your device.
  • Desktop applications install on your computer and run locally; web applications run in your browser and store data on a company's servers.
  • Mobile applications are built for phones and tablets and are usually downloaded from an app store specific to your device's operating system.
  • Proprietary software is owned by a company and costs money; open-source software is free and its code is publicly available for anyone to inspect or modify.

Desktop applications versus web applications

A desktop application installs directly on your computer and runs from your hard drive. Microsoft Word, Adobe Photoshop, and Slack are desktop applications — you download them, install them once, and they sit on your machine. They work whether or not you are connected to the internet (though some features may require a connection). When you open them, they load from your local storage, which is usually faster than waiting for something to load from the internet.

A web application runs inside your browser — Chrome, Firefox, Safari, or Edge. Gmail, Google Docs, Canva, and Figma are web applications. You do not install anything; you just visit the website and log in. Your files and settings are stored on the company's servers, so you can access them from any device with a browser and an internet connection. The trade-off is that web applications require an internet connection to work, and they are generally slower than desktop applications because data has to travel back and forth to a server.

Many companies now offer both. Microsoft, for example, sells Word as a desktop application and also offers Word Online as a web application. Google offers Google Docs only as a web application. The choice between them usually comes down to whether you need to work offline, how much processing power you need, and whether you want your files stored locally or in the cloud.

Mobile applications and app stores

A mobile application is built specifically for a phone or tablet. iOS apps (for iPhones and iPads) come from the Apple App Store. Android apps (for most other phones and tablets) come from the Google Play Store, though some Android devices have alternative app stores. Mobile apps are usually smaller and simpler than their desktop cousins because phones have less processing power and storage.

Mobile apps are downloaded and installed on your device, but they are managed by the app store — you can update them all at once, and the store handles removing old versions when you delete an app. Many mobile apps have a web version or a desktop version that does the same thing, but the mobile version is optimized for a touchscreen and smaller screen size.

Some applications exist only on mobile — Instagram, TikTok, and Snapchat started as mobile-only apps. Others, like Microsoft Office, started on desktop and added mobile versions later. A few, like Google Docs, work equally well on mobile through a web browser or a dedicated app.

Proprietary software and open-source software

Proprietary software is owned by a company. You pay for it (either as a one-time purchase or a monthly subscription), and you are not allowed to see or modify the code that makes it work. Microsoft Office, Adobe Creative Suite, and Slack are proprietary. The company controls updates, features, and pricing. If the company stops supporting the software, you cannot fix it yourself.

Open-source software is free and its source code is publicly available — anyone can read it, modify it, and redistribute it. LibreOffice (a free alternative to Microsoft Office), GIMP (a free alternative to Photoshop), and Firefox (a web browser) are open-source. Because the code is public, many people can contribute improvements, and you can modify the software to suit your needs. The downside is that open-source projects often have less polished interfaces and fewer features than proprietary equivalents, though not always.

The choice between proprietary and open-source usually depends on your budget, how much support you need, and whether the software does what you want. Open-source is a good option if you want to avoid subscription costs or if you need to customize the software. Proprietary software is often easier to learn and has more professional support behind it.

Subscription software versus one-time purchase

Most application software today is sold as a subscription — you pay a monthly or yearly fee to use it, and the company provides updates and support. Microsoft 365 (formerly Office 365), Adobe Creative Cloud, and Slack all work this way. The advantage is that you always have the latest version and new features as soon as they are released. The disadvantage is that you never own the software — if you stop paying, you lose access.

Some software is still sold as a one-time purchase — you pay once and own a license to use that version forever. Older versions of Microsoft Office worked this way. The advantage is that you own what you buy and do not have recurring costs. The disadvantage is that you do not get updates automatically, and the company may stop supporting the version you own.

A few applications use a freemium model — the basic version is free, but you pay for advanced features. Spotify, Zoom, and Canva work this way. This lets you try the software before committing money, but the free version is usually limited in ways designed to push you toward paying.

How application software relates to your operating system

Your operating system is the foundation that application software runs on. Windows, macOS, Linux, iOS, and Android are operating systems. They manage your hardware (processor, memory, storage, screen), handle basic tasks (file storage, printing, networking), and provide a standard way for applications to request resources from your device.

When you install an application, it is built for a specific operating system. A Windows application contains code that knows how to talk to Windows. A macOS application is built to talk to macOS. This is why you cannot just copy a Windows program onto a Mac — the Mac does not understand the Windows code. Some companies release versions of the same application for multiple operating systems (like Chrome, which runs on Windows, macOS, Linux, iOS, and Android), but each version is built separately.

This also means that when you upgrade your operating system, some older applications may stop working because they were written for an older version. Developers have to update their applications to stay compatible with new operating system releases, and some choose not to.

Common types of application software

Application software is organized by what it does. Productivity software includes word processors (Word, Google Docs), spreadsheets (Excel, Google Sheets), and presentation tools (PowerPoint, Keynote). Creative software includes photo editors (Photoshop, GIMP), video editors (Premiere, DaVinci Resolve), and design tools (Figma, Adobe Illustrator). Communication software includes email clients (Outlook, Gmail), messaging apps (Slack, Teams), and video calling apps (Zoom, Google Meet).

Other categories include media players (VLC, iTunes), file managers (Windows Explorer, Finder), web browsers (Chrome, Safari, Firefox), and utilities (antivirus software, backup tools, password managers). Games are also application software — they run on your device and do one main thing, which is provide entertainment.

Most people use a mix of these categories. A typical computer might have a web browser, a word processor, an email client, a file manager, and a few specialized tools for work or hobbies. A phone typically has a web browser, email, messaging, a camera app, and a handful of other apps you download from the app store.

Frequently Asked Questions

What is the difference between an application and a program?

The terms are used interchangeably in everyday language. Technically, a program is any executable code, while an application is a program designed for end users to accomplish a task. In practice, people use "app" for mobile software and "application" or "program" for desktop software, but they mean the same thing.

Can I use the same application on my computer and my phone?

Sometimes. If a company offers versions for both platforms — like Microsoft Office, Google Docs, or Slack — you can use the same account and files on both. However, the mobile version is usually a separate download and may have fewer features than the desktop version. Some applications exist only on one platform.

Why do some applications require an internet connection and others do not?

Desktop applications and mobile apps can work offline because they run locally on your device. Web applications require an internet connection because they run on a company's servers and send data back and forth. Some applications (like Google Docs) can work offline but sync your changes when you reconnect.

Is open-source software less safe than proprietary software?

Not necessarily. Open-source software is reviewed by many people, which can catch security problems quickly. Proprietary software is reviewed by the company's team only. Both can have security flaws. The difference is that with open-source, you can see the code and verify it is safe; with proprietary, you have to trust the company.

What happens to my data if an application stops being supported?

If it is a web application, your data is on the company's servers — if they shut down, you lose access. If it is a desktop application, you can usually export your data to a standard format (like PDF or CSV) before the application stops working. Always keep backups of important files in a format that other applications can read.