@StorageNinja said in TPM module - what is it used for?:

Real encryption keeps the keys in a remote KIMP server (what you'll see for any DISA/STIG system etc).

I've seen shops that require a human to apply the key every time.

PTT is a way of provider TPM, they are not two separate things. PTT is a non-dedicated hardware approach to TPM 2.0. PTT is designed for low power devices, often used in industrial computing.

Traditionally TPM requires a TPM module, a dedicated hardware processor and firmware for security. With TPM 2.0 dedicated hardware is no longer required. PTT is Intel's implementation of TPM 2.0 for low power systems.