There are two mode of deployments:
- Firewall Mode
- IPS Mode
For each mode, we have others modes
- Router Mode
- Transparent Mode
- Inline Mode
- Inline Tap Mode
- Passive Mode
The confusion is between Inline mode and Transparent Mode. Both work like bumps in the wire, which means they are invisible to the connected devices. However, they are two different techniques.
Inline mode can be used when we are using a Firepower as an IPS-only device in which most firewall services are not working.
Inline mode differs from transparent mode, in which multiple interfaces can be added in each bridge group and each bridge group behaves like an isolated switch.
Transparent mode is used as a mode when we use Firepower as a firewall service, which can also be used as an IPS device at the same time.