What is the difference between central sleep apnea and regular apnea?

Obstruction vs CO2: Central apnea is caused by the brain's inability to respond to elevated co2 (carbon dioxide) levels in the blood. Obstructive sleep apnea is caused by the collapse of the airway when the muscles of the throat, tongue, and possibly the palate when they are flaccid/paralyzed during the deeper stages of sleep. Osa responds well to CPAP and dental devices. Central may not.

Layman terms: Central is controlled by the brain when blood carbon dioxide level gets high brain gets a signal and you breathe in oxygen obstructive apnea happens when there is an obstruction in the airway passage whether in the nasal passage or by tongue in the oral passage.