EC2 EBS device id confusion dev sdf vs dev xvdf

Question

I attached an EBS volume to my EC2 instance, turned it into an EXT3 file system, and successfully mounted it. However, I was thrown off a little bit initially mainly due to what the AWS console said my EBS device ID was.

According to the AWS console:

i-xxxxxxx :/dev/sdf (attached)

I took this to mean that my attached EBS device id was /dev/sdf. So when I attempted to turn the device into a file system using this device id, I received the following error message.

ubuntu@ip-xx-xx-xx-xx:~$ mkfs -t ext3 /dev/sdf

mke2fs 1.42 (29-Nov-2011)

Could not stat /dev/sdf --- No such file or directory.

The device does not exist; did you specify it correctly?

Then after researching a little bit, I found this article and then subsequently found out by running cat /proc/partitions that my true device id was /dev/xvdf not /dev/sdf.

My question is why is the AWS console saying it's /dev/sdf when it's actually /dev/xvdf?