What does a certified criminal record mean for an ED visa application in Thailand?

Hello everyone, I'm planning to apply for an ED visa at the thai embassy in Kuala Lumpur next week. I've downloaded a checklist from their website about which documents I'll need.

One of the documents says "Certified criminal record in the applicant's country of origin or in Thailand (for private course/program provider only)"

What do they mean by that? What is a private course/provider program? I'm not gonna teach anything, I'm planning to study thai.

Should i go to a police station to get a statement?

Thanks in advance