While it’s more energy efficient to have a monitor go to sleep, or better yet, have it turned off when you’re not actively using it, a screensaver shows you something beside a black screen. The reason it’s called a screensaver is that an analog monitor with an unchanging display over time could develop burn-in – with an LCD display basically the same risk is called persistence. To mitigate that risk a screensaver ideally regularly changes the color of every pixel, so no pixels constantly display the same color [black doesn’t count]. Note then that 2 of the examples included, Aquarium & Matrix, fulfil that requirement, with the other three having portions of the image remain static, and so if left on long enough could potentially cause the problem screensavers are supposed to prevent.
You can just as easily play a video full screen – some popular You Tube videos are completely black, just for that purpose – but screensavers traditionally offer a smaller file size, relying on the PC or laptop graphics to generate what you see on screen. Some PCs &/or laptops may not be able to fully display the screensavers you create. If your PC or laptop has a discreet GPU, e.g., a separate PC graphics card, the screensavers you make with Animated Screensaver Maker may use it somewhat extensively, using more current and generating more heat. [You can use something like the portable CPUID HWMonitor, clearing the minimum & maximum columns, then testing a screensaver – afterwards the max value should show you how much of both.] That said, you can easily add motion FX and/or sprites to a static image to create something unique.
Animated Screensaver Maker adds two folders to Documents – one for examples & the other for templates – along with the program’s folder, while several individual files are added to C:\ Windows\ -- Animated Screensaver Maker Uninstaller.exe, WebUpdateSvc4.exe, WebUpdateSvc4.log, wuwuninst.exe, WebUpdateSvc4.INI, wuw4.dll, WuWUI.exe. I recorded 150 registry entries added in my Win11 VM – the ones that matter are: 2 keys for .asw files, 6 keys, including a service, for the app’s auto update, 2 keys for uninstall, 1 key for the app itself, and 1 key for activation.