A software application is a program you run on your device to do a specific job
A software application (or app) is a set of instructions that tells your computer, phone, or tablet to perform a task. When you open Microsoft Word to write a document, use Spotify to play music, or tap Instagram to see photos, you are running a software application. Each one is built to do something particular — word processing, music streaming, social media — rather than everything your device can do.
Applications sit on top of your device's operating system, which is the foundation that makes the hardware work. The operating system (Windows, macOS, iOS, or Android) handles the basic functions like managing files and connecting to the internet. Applications use those basic functions to do their specific work. You cannot run an application without an operating system, but you can have an operating system without any applications installed.
Applications come from different sources. Some come pre-installed on your device when you buy it. Others you download from the internet — from official stores like the Apple App Store or Google Play, or directly from a company's website. Some are free, some cost money, and some are free but show advertisements.
Key Takeaways
- A software application is a program designed to do one specific job, like editing photos, managing email, or playing games.
- Applications run on top of your operating system and cannot work without one, but your operating system can work without any applications installed.
- You can download applications from official stores like the Apple App Store or Google Play, or directly from a company's website.
- Desktop applications (on computers) and mobile applications (on phones and tablets) are built differently because the devices work differently.
- An application stays on your device until you uninstall it, unlike a website which you visit and then leave.
Desktop applications versus mobile applications
A desktop application is a program you install on a computer — Windows, Mac, or Linux. Examples include Adobe Photoshop for photo editing, Microsoft Office for documents and spreadsheets, and Google Chrome for browsing the web. Desktop applications usually take up more space on your hard drive and use more of your computer's power, but they often have more features because computers have more resources to work with.
A mobile application is a program you install on a phone or tablet running iOS or Android. Examples include TikTok, Gmail, and Uber. Mobile apps are built to work with a touchscreen and to use less battery and storage space than desktop versions. Many companies make both a desktop and a mobile version of the same application — they look different and work differently because the devices are different, but they do the same core job.
Some applications work in a web browser instead of being installed on your device. Google Docs, Canva, and Figma are examples. These are sometimes called web applications. You do not install them; you visit them in your browser like a website. The difference is that a web application stores your work on the internet and lets you do complex tasks, while a website usually just shows you information.
How applications get onto your device
When you buy a new computer or phone, it comes with some applications already installed — your operating system, a web browser, maybe a calendar or calculator. These are called pre-installed applications. You do not have to do anything to get them; they are ready to use when you turn on the device.
To get more applications, you download them. On a phone or tablet, you open the official app store for your device — the Apple App Store if you have an iPhone or iPad, or Google Play if you have an Android phone. You search for the application you want, tap a button to download it, and it installs automatically. On a computer, you might download from an app store (like the Microsoft Store on Windows), or you might go directly to a company's website and download the installer file.
Before you can use an application, you usually have to agree to its terms of service and privacy policy. These are the rules the company sets for how you can use the application and what they do with your information. You do not have to read every word, but it is worth knowing that you are giving the application permission to access certain things on your device — your location, your contacts, your photos, or your microphone.
What happens when you run an application
When you open an application, your operating system loads the program from your hard drive or storage into your device's memory (RAM). The application then starts running and displays a window or screen where you can interact with it. Everything you see — the buttons, the text, the images — is part of the application.
While the application is running, it uses some of your device's processing power and memory. If you run many applications at the same time, your device can slow down because it is dividing its resources among all of them. This is why closing applications you are not using can make your device faster.
When you close an application, it stops running and releases the memory it was using. Your work is usually saved to your device's storage (or to the internet if it is a web application), so you can open the application again later and pick up where you left off. Closing an application does not delete it from your device — the application files stay there until you uninstall it.
Updates and why applications need them
Software companies regularly release updates to their applications. An update is a new version of the application that fixes problems, adds new features, or improves security. When a security problem is discovered, an update patches it so hackers cannot exploit it. When users report bugs (things that do not work right), an update fixes them. When the company wants to add a new feature, an update delivers it.
Most applications check for updates automatically and notify you when one is available. On phones and tablets, you can usually set applications to update automatically in the background. On computers, you might see a notification asking if you want to install an update, or you might have to check manually in the application's settings.
It is a good idea to install updates when they are available, especially security updates. Delaying updates leaves your device vulnerable to problems. However, sometimes an update changes how an application works in ways you do not like, or it introduces new bugs. If that happens, you usually cannot go back to the old version.
Uninstalling applications you no longer need
If you want to remove an application from your device, you uninstall it. On a phone or tablet, you usually press and hold the application icon and select "Remove" or "Uninstall." On a computer, you go to your settings or control panel, find the application in the list of installed programs, and click "Uninstall."
When you uninstall an application, the program files are deleted from your device and you free up storage space. However, some data associated with the application might remain — settings you changed, files you created, or login information. If you want to completely remove all traces of an application, you might need to manually delete these files, though this is rarely necessary.
Uninstalling an application does not affect your operating system or other applications. You can reinstall the same application later if you change your mind, and you will usually be able to download it again from the same place you got it the first time.
Free applications, paid applications, and subscriptions
Some applications are completely free and have no hidden costs. Others cost money upfront — you pay once and own the application forever (or until you uninstall it). Still others are free to download but show advertisements, or they are free with limited features and charge money to unlock the full version.
Many applications now use a subscription model, which means you pay a monthly or yearly fee to use them. Microsoft Office 365, Adobe Creative Cloud, and Spotify are examples. With a subscription, you do not own the application; you rent access to it. If you stop paying, you lose access. The advantage is that you always get the latest version and new features automatically.
Before you download an application, check whether it is free or paid. On app stores, the price is usually shown clearly. If it says "Free," it is free to download, but it might show ads or ask for money later. If it says a dollar amount, you will be charged that amount when you download it.
Frequently Asked Questions
What is the difference between an application and a website?
A website is a collection of pages you visit in your web browser; you do not install it on your device. An application is a program you install and run on your device. Websites are accessed through a browser, while applications have their own interface. However, web applications blur this line — they run in your browser but work more like installed applications.
Can I run the same application on my computer and my phone?
Many companies make versions of their application for both computers and phones, but they are technically different programs built for different operating systems. You download the computer version on your computer and the phone version on your phone. Your files and settings might sync between them if the company supports that, but they are separate installations.
Why do applications ask for permission to access my location or camera?
Applications request permission to access sensitive features on your device for security reasons. Your operating system requires the application to ask your permission before it can use your camera, microphone, location, contacts, or photos. You can usually change these permissions in your device's settings if you change your mind about what an application can access.
What should I do if an application keeps crashing?
First, try closing the application completely and opening it again. If that does not work, check if there is an update available and install it. If the problem continues, try uninstalling and reinstalling the application. If it still crashes, the problem might be with your device's storage or memory — try closing other applications or restarting your device.
Do I need to uninstall applications I do not use?
You do not have to, but uninstalling unused applications frees up storage space and can make your device slightly faster. However, if you think you might use an application again, you can leave it installed since storage space is usually not a problem unless your device is almost full.