What kind of email address does my student need?

Does a student need a Gmail account?

can a student sign into files with an icloud account

A student can use any type of email address.

Your CounselMore your account is connected to your chosen Google Drive. You are sharing your Google Drive with the students email address, which can be any email address - Google asks that every email address authenticate before gaining access to anything in the Google territory. So while any type of email address can be used, every type of email address must authenticate against Google - which only means that Google is asking for the email address and then asking for the ability to read the email address that the browser window is currently assigned to - it is only authenticating that who the person says they are is who they are on the device they are using - which provides a great deal of security.