AsheGuy wrote:
"Apps" (short for applications) is the equivalent of "programs", the original term used to describe a set of instructions (code) that runs on a computer to perform a specific task.
Originally, the only way on a computer to run a program (or application) was to install that program on your computer. Later, the Internet came along and you could perform tasks via an Internet based application on a server somewhere and it is accessed through a web browser.
When smartphones and tablets came along, this was the environment that existed. These devices are simply computers like those that took up a large room but in a very more compact form.
As to the OP's question, installing an app on a smart phone or tablet means you are downloading and installing the code for that task on your device rather than perform that task using an application/program on a remote server somewhere via a web browser. This allows that application to be tailored to the functions available on your device rather than operate within the constraints of a web browser application that must operate on all the platforms that a web browser can run on. In many ways that is a plus but in the case of privacy and security it can be a minus because the app can access functions of the device not available to a web browser although this distinction is somewhat muddied in the case of cloud computing.
This is a great description and I’ll add that the App can be more fully featured and may be easier to use since the user interface is completely decided by the app developer. I’ve also seen apps that were terribly done or had less features than their website counterparts.