$1.(10$ marks$)$ Answer the following questions.

$($a$)(4$ marks$)$ In ER modelling of constraints on binary relationship types, there are two labelling options discussed in the lectures, i$.$e$.,$ the cardinality ratio together with the existence dependency con$-$ straint, and the $($min$,$ max$)$ notation. Describe the two labelling mechanisms as well as the difference between them?