[Nil]

We've all heard of dual booting, but linux and windows dont go too well.
so is it possible that i buy an external hard drive and install linux on it.
can it be booted by selecting USB as a first boot. will it boot the linux with full capabilities on my laptop?
i want to install antergos linux.
while my internal laptop hard drive will have windows 10.

does it have any complications?

What do you mean Windows and Linux don't go well while dual booting?

But yes, you can install Linux on an external drive and this is often called making a bootable drive. Keep in mind that depending on your computer, the speeds while using this OS can be limited by the USB transfer speeds (should be fine with USB 3.0). I would look up tutorials, because you're going to need to partition the external drive correctly, and I believe there are tools that will help or do this for you. You'll have to enter your BIOS settings on boot and choose to load the bootable drive.

I'd prefer to just dual boot though, especially if you don't actually need the portability of having a bootable USB drive.