What Is a Smartphone App?

By Aaron Parson

Apps, short for applications, are what separate smartphones, including iPhones, Android phones and Windows phones, from the boring cell phones of years past. Just as the programs on your computer range from word processors to games, apps come in all types: work and play, free and paid, simple and elaborate. So when Apple trademarked the now-famous slogan, "There's an app for that," the message was that no matter what you wanted to do on an iPhone, you could find a way.

Built-in Apps

To make sure a smartphone grabs your attention right out of the box, manufacturers build in a range of apps. Although the exact apps vary from phone to phone, the basics almost always include an app for checking your email, an app to browse the Web, an app for taking notes and other such utilities. Other than their inclusion with the phone, the most important distinction from other apps is that you can't delete most built-in apps. Unfortunately, some manufacturers include so many apps -- many of which you won't ever use -- that you end up with far less free space on your phone than you expected, leading to the term bloatware for unwanted factory-installed apps.

Downloaded Apps

Installing apps downloaded from the Internet expands a smartphone's abilities beyond its built-in apps. On iPhones, apps come from the App Store, while most Android phones use the Google Play Store, though Android also supports installing apps from other websites. Despite the term "store," many apps are completely free, and even paid apps often have lite trial versions. As an alternative to these two options, some developers also offer freemium apps, which install for free but include paid add-ons or unlockables. Freemium apps have caught on with developers and phone owners to such a degree that in-app purchases account for 98 percent of the revenue on the Play Store, at the time of publication.

Web Apps

Back when Apple first released the iPhone, it didn't provide a way for developers to build new apps, and the App Store didn't come out until the second version of the system software. Instead, developers had to create Web apps, which run from inside a Web browser. Even today, many services still use Web apps in addition to, or in place of, regular native apps. Once loaded in a browser, such as Safari on the iPhone or Chrome on an Android, a Web app behaves more like an app than a website, offering a self-contained experience that fits the phone's screen. For example, you can either run the native YouTube app installed through your phone's app store, or you can visit YouTube's website in your phone's browser to reach a Web app with a similar design and functionality to the native app.

An App for Every Task

The largest difference between the concepts of smartphone apps and computer programs is that almost every task on a phone uses an app. For example, on a PC, you might open the Windows Control Panel to change a setting, look at photos in a folder and then rearrange your files, all without running a program. On a smartphone, each of these tasks uses a different app: a settings app for changing system options, a photo viewing app to look at pictures and a file manager app to organize your documents. Even many services that run in a Web browser on a computer require native apps on your phone. For example, you can't visit the Netflix or Hulu website on your phone to watch a movie; you need the Netflix app or the Hulu app.