Perusikkuna

Perusikkuna is a Finnish term used in graphical user interface (GUI) design to denote the primary window of an application, essentially the main or basic window that serves as the key container for user interaction. The term combines perus- meaning “basic” with ikkuna meaning “window,” and it is commonly found in Finnish software documentation and educational materials.

Its role is to provide the main stage for the application's user interface. A perusikkuna typically includes a title bar, window borders, and standard window controls, and may host menus, toolbars, a status bar, and a central content area. The window operates within the host operating system's window manager and can be resized, moved, minimized, or closed.

Implementation varies by toolkit, but in most GUI libraries the perusikkuna is a top-level or root window created at application startup. It handles events such as user input, resizing, and closing. Closing the perusikkuna may terminate the application or merely hide the window, depending on the framework and settings. The content area is responsible for presenting the application's primary interfaces and controls.

Terminology varies: some Finnish sources prefer “pääikkuna” (main window) or other terms. Perusikkuna often appears in educational contexts to illustrate a simple, self-contained window, while more complex applications may include multiple windows or dialogs. In English, the closest equivalent is the main window or main form, and in practice the terms are not always interchangeable across frameworks.

Related concepts include the main window or top-level window in GUI toolkits, as well as general GUI programming and window management.