It means that when you turn on your computer, you get to choose between Android and Windows. Android is a mobile OS, so great if you're just Surfing the web, but if you want a fully functioning computer then select Windows.
boot loader
You can dual boot anything; as long as they are on different hard drive partitions.
It's possible, as there are DIY's on how to do it. A more commercial application is using the BlueStacks app player, which allows Android apps to run in a Windows or Mac OS environment. Some manufacturers are also coming out with desktops, laptops, and tablets that can dual-boot Android and Windows.
You can use the Boot tab of MSConfig to find out if the computer is using a dual boot configuration.
You can have more than one operating system installed on a computer at a time. Dual boot allows you the choose which system you want to use. With dual boot enabled, when you turn on your PC it will give you a choice of operating systems.
Dual-boot and Multiple-Boot are pretty much synonymous.
Boot loader in Android is something similar like you have boot loader over the Windows PC. I am sure you know that when you ran onto trouble you boot your PC over the boot loader menu to perform recovery ! It's the same thing when you encounter problems with your Android device, boot loader is used to get the device back in working state.
Dual Boot
dual boot
Dual-boot means to have more than one operating system installed on your hard drive, and to switch between them when you start your computer.
Dual boot
Yes.