One scenario: Internal audit independently audits procedures, practices, etc. at an in depth level...with samples, write ups, etc. Time consuming. Compliance is copied on the reports to learn about possible problems,i.e. hold practices don't follow regs. Compliance would then follow up with dept, have extra training etc. etc. Compliance may also be in charge of a program but where responsibility is assigned to various other peeps who will provide reports, etc. to Compliance. Compliance does no actual testing a la audit, except when a new reg is issued and Compliance should then check to make sure all the elements needed are, in fact, in play.Compliance is the big picture. Audit tests Compliance's programs, procedures, etc.