Chromebook laptops are designed mainly for Chrome OS. They don’t officially support Windows, but there are several unofficial ways how to install it and run it. Chromebooks often have solid CPUs and plenty of RAM, so they can match the minimum hardware requirements for Windows 10 installation.
So it is possible to replace Chrome OS with Windows on Chromebook, but not on every model. The replacing of Chrome OS with Windows is a bit complicated and takes more time, because you need UEFI BIOS to boot and install Windows 10.
Because of that, you might need to replace Chromebook's BIOS with the UEFI BIOS. It also could happen that Windows don’t have hardware drivers for every Chromebook hardware like the touchpad, keyboard etc. In this case you can try to search for the third-party drivers online.