Sitting on top of and utilizing the features of a web server is the web application. So what exactly is a web application? This seems to be the source of some confusion, so let’s address that.
In essence, a web application is software that is installed on top of a web server and is designed to respond to requests, process information, store information, and scale in response to demand, and in many cases it is distributed across multiple systems or servers.
As opposed to a few years ago, web applications come in three variations today:
- Browser based, which include code that may have been partially processed on the server but is executed in the web browser itself. Such an application has the ability to access data stored on a server as well as on the local system or both, depending on design.
- Client based, which are essentially the same as browser-based applications, but instead of being run within the browser environment, they’re run as their own
application. Applications that require their own client-side application to be installed prior to using the web application fit into this category.
- Mobile apps are by far the type most commonly encountered today. To be included in this category the application typically runs on a mobile OS such as those running on smartphones and tablets, mainly Google’s Android or Apple’s iOS. So what do all of these types have in common? Each one of them in some capacity processes information on a server before providing the information to the client side of the equation. Simply put, the bulk of the processing is done remotely and the results are presented locally.