android internal memory named as /sdcard/ folder in root (Samsung Captivate)?

[guy_next_door]

When I check the root of my phone (Samsung Captivate), I found out that my internal memory is named /sdcard/. When I bought a new micro sd card, the phone mounts my card inside /sdcard/ folder and named it as /sd/. So when I try to root my phone, I put it on the internal memory not on the sd card folder.

Shouldn't my micro sd card be mounted on the root not on the internal memory? Shouldn't the internal memory be named differently? What's the correct name for the internal memory if it's not /sdcard/? If this is not the right folder name, how can I fix it?

Thanks in advance