In Ettercap $($Man$-$in$-$the$-$Midlle attack$),$ usually we add Targets as $1$ and target $2$ as:

a$.$

Ettercap can not be used for Man$-$in$-$the$-$Middle, it is only used for ARP poisoning

b$.$

Taregt $1$ is the defaut gateway, and target $2$ is the victim's IP

c$.$

Taregt $1$ is the victim's IP$,$ and target $2$ is $192\mathrm{.}168\mathrm{.}1\mathrm{.}1$

d$.$

Ettercap is only used to sniff Packets. Wireshark determines the targets