What information do potential co-op employers have access to?

I’m in the middle of the co-op interview process, and I’m wondering what parts of our record a potential employer can see. If we don’t include a transcript in the application, can they see our transcript some other way? Also, can they see OSCCR records?

They only get what you send them - so usually just a resume / cover letter / recommendations if applicable - some ask for additional stuff like a transcript but most don’t.