respective和several都有“各自的”意思,但具体用法有什么不同吗?

respective是各自的,但several与其说是各自的意思不如说是各种、几个.
each student have their respective student number.每个学生有他们各自的学号.
each class have several students who have the same birthday.每个班级都有几个学生的生日在同一天