In an offline situation, this is commonly achieved by performing a roll call, and marking each student present, absent, late, sick, etc. in a book, the "register".
If a new student joins the course, they can easily be added to the end of the register. If the student leaves the course, they can be marked as such.
I understand how to enrol students onto a course, and there are ways of monitoring their participation, but what about a present / absent tool...?
Thank you for your interest - I hope to hear your reply