Bootsplash

A bootsplash, also known as a bootscreen, is a graphical representation of the boot process of the operating system.
A bootsplash can be a simple visualization of the scrolling boot messages in the console, but it can also present graphics or some combinations of both.
Unlike splash screens, bootsplash is not necessarily designed for marketing purposes, but can be to enhance the experience of the user as eye candy, or provide the user with messages (with an added advantage of color-coding facility) to diagnose the state of the system.
Microsoft Windows.
All versions of Microsoft Windows feature a boot screen, which is loaded during the startup process. With extra, third-party utilities, it is possible to replace the default Windows boot screen with custom images, text, and/or animations.
Windows Vista.
In Windows Vista, the default boot screen is represented by a green indeterminate progress indicator. The boot screen can be changed so that it displays a static image of an aurora with the text, "Starting Windows Vista" by enabling the "No GUI boot" option within the Windows System Configuration Utility (msconfig.exe). Microsoft would update the aurora image throughout the lifecycle of the operating system, starting with the first service pack, where it was altered to match the image displayed during the operating system's hibernation screen.
Windows 7.
In Windows 7, the change of the boot screen, although possible through third-party utilities, is extremely risky and may cause the system to be unable to boot. Also, the hidden "Aurora" boot screen was removed.
Windows 8, 8.1, 10.
If the system is UEFI boot (not Legacy boot) and the ACPI BGRT table is present, Windows 8 and later will display the OEM logo during startup.