What does "be the inclusion" mean?

Question

Can anyone explain what the phrase means? To be specific, my notes has the phrase "let $f:A \rightarrow B $ be the inclusion". Does this mean the identity map?

Answer 1

It means that $A\subseteq B$ and that $f(a)=a$ for every $a$ in $A$. But $f$ is not the identity map unless $B=A$.