Kerodon

$\Newextarrow{\xRightarrow}{5,5}{0x21D2}$ $\newcommand\empty{}$
$\Newextarrow{\xhookrightarrow}{10,10}{0x21AA}$

Question 8.5.0.5. What is the correct $\infty $-categorical counterpart of the notion of an idempotent endomorphism?