An application is user-facing software that is installed on or otherwise runs on a personal computing device.
Games, email and messaging clients, and business and productivity suites are all examples of applications. Some types of applications are installed on the operating system of a computer (desktop applications) or mobile device (mobile applications or mobile apps). Others are accessed through an internet browser (web apps).
Applications may be installed via physical media such as a DVD or USB stick, downloaded from the internet, or through portals known as app stores. Google Play, the largest app store, contained more than 3 million applications as of 2020, according to Statista.
History of Applications
Early computers took up entire rooms, had no screen, keyboard or mouse, and were controlled by physical punch cards. They were primarily used by researchers and academics, far out of the reach of the general public.
In 1968, however, engineer Douglas Engelbart hosted “The Mother of All Demos” in California. At this event, he showed the use of a keyboard, the newly termed mouse, and a graphical user interface. These demonstrations showed word processing and hyperlinking capabilities, making them a starting point for applications as we know them.
In the subsequent decades, computers jumped from laboratories and universities into people’s homes. The development of software applications followed closely with the advancement of computer hardware. As computers became more powerful, screens became more capable and storage more accessible, applications progressed. Very quickly, word processors, spreadsheets and graphics editors became available to users.
Types of Applications
Desktop applications run on a desktop or laptop computer and rely on keyboard, mouse and/or touchscreen inputs from the user. They operate locally and do not have to rely on the internet for functionality.
Mobile apps are designed specifically for devices such as smartphones and tablets, which typically have less computing power than desktops or laptops. They also rely mostly on touchscreen-related user inputs, such as taps, swipes and drags, instead of a keyboard and mouse. Many mobile apps are responsive, meaning they automatically adjust to optimally display on various screen sizes and orientations.
Web applications are accessed through web browsers over the internet. These applications are not downloaded onto devices, and maintenance is handled by the software provider. Web applications can be accessed anywhere by anyone, on any device, as long as there is an internet connection.
Code vs. Program vs. Application
In essence, from code to application, one is going from very broad to more specific.
Code refers to the actual characters written when creating a computer function. Coding languages, which have their own grammar and syntax to command computers to execute tasks, are the basis of all programs and applications.
A program takes the concept of code one step further. A program is a collection of code that works coherently to perform a function. This could be system software that coordinates hardware, but it also could be an application.
Applications are more specific than programs because they always involve a user. The premise of a software application is to perform some task based on user input. Not all programs meet this definition.