Assignment Manager vs Territory Management

We are currently using Assignment Manager to assign sales reps and csrs to accounts, contacts, and opportunities based on state and county for one account type. For a second account type, we need to assign an account to a territory based on the primary sales rep (position) on the account.

Can someone help me understand the difference between Assignment Manager and Territory Manager in Siebel?

Are they each stand-alone or do they work together?

Todd Bachamp