I have two internal hard drives in my pc, one has windows 11 and one is for extra storage.

I hooked up an external USB drive to install Linux onto. During the install it says

Device for boot loader installation

And then it gives me a number of options

/dev/nvme0n1 (this I think is what my windows 10 is at)

/dev/nvme0n1p1

/dev/nvme0n1p3

/dev/nvme0n1p4

/dev/sda ATA WDC WD10EZEX-00W (1.0 TB) Ii think this is the other internal drive

/dev/sda2

/dev/sdb WD easystore 2647 (1.0 TB)

/dev/sdb1

I think the easystore is my external drive. The problem is they are both 1T in size and both western digital.

How do I know which is which?

Just above where it says "device for boot loader installation" it shows

If I try to click on /dev/sdb I can't click on install now.

On the basis that I should be trying to install in /dev/sdb what am I doing wrong to actually start the install process?

Yeah I'm new to Linux. I need help to do it right and not nuke my windows install