Is Web browser is a web application or window application?

A web browser is technically a desktop (or window) application, not a web application.

Because,

A web browser (like google Chrome, Mozilla Firefox, Microsoft Edge, or Safari) is installed on your operating system and runs locally on your computer or device. It provides the platform or interface that allows users to access and interact with web applications through the internet.

On the other hand, a web application is a program that is hosted on a remote server and accessed via the browser. Examples of web applications include Gmail, google Docs, or online banking systems.

In summary:

Web browser = desktop/window application (installed on your device)

Web application = software accessed through a browser (runs on the web)

So while a browser enables you to use web applications, it itself is a window/desktop application.