Web applications are independent of the operating system of the terminal / end device. The applications are being opened via internet browser. Simply expressed web applications are websites with a significant higher interactive value.
The functionality of web applications is developed with JavaScript while the presentation is of course done via the web standards HTML and CSS. Modern web applications are in terms of functionality similar to classic workstation software. The main difference being that in the case of web applications data processing usually takes place directly on a server (backend). The local computer represents only the frontend, i.e. the user interface. The web application can be run with any current web browser and does not have to be installed locally.
In addition the data can also be acceded on any other device, from any location with internet access, if the URL and - where required - user name and password are known. Web applications are mostly responsive. Meaning they are optimized for all screen sizes and as easy to use on a personal computer as on a tablet.