It means the case is closed or completed and no further action is going on within it. That's whey they say its inactive. If you still have questions, consult with a local attorney.
Although very imprecise, when the Clerk of Court puts a docket entry that reads "closed" or "inactive," it only means that it is dormant. To ensure that the case is resolved, the case must be dismissed or result in a conviction or acquittal, if it is a criminal case. You need to determine which is the resolution to then expunge it from the record, if possible. Consult with a Maryland atorney.