That's correct.

Basically it's dedicated device for Drive Encryption/Bitlocker. It provides the benefit of Integrity Checking when the computer is offline to detect if there has been any tampering.

For example,
Moving the BitLocker-protected drive into a new computer.
-Installing a new motherboard with a new TPM.
-Turning off, disabling, or clearing the TPM.
-Changing any boot configuration settings.
-Changing the BIOS, master boot record, boot sector, boot manager, option ROM, or other early boot components or boot configuration data.


It's pretty common on servers and business grade computers/laptops (e.g. Lenovo ThinkPad/ThinkCentre)

It looks something like this:
[Linked Image from i.ebayimg.com]