In-line deployments can be either Bridge mode or Router mode (Router mode supports both in-line or Out-of-path deployment where data traffic is redirected by using PBR, WCCP or VRRP in Out-of-path setup). While Bridge mode connects 2 of a single segment, Router mode connects 2 different subnets on each interface. Further, bridge mode is provisioned in simpler setups while Router mode deployments are mostly for complex setups. Another important consideration in Bridge mode is that Data path address is assigned to BVI and not to LAN or WAN interface. One the other hand, in Router mode, data path addresses are assigned to LAN and WAN interface.
Below table illustrates the difference in Bridge mode and Router mode –