1. Non-Invasive Ventilation (NIV): This includes methods like CPAP and High-Flow Nasal Cannula (HFNC) that provide respiratory support without an endotracheal tube. 2. Invasive Ventilation: Involves inserting an endotracheal tube to deliver mechanical ventilation. This can be further categorized into: - Conventional Mechanical Ventilation (CMV): Uses standard ventilators with modes like synchronized intermittent mandatory ventilation (SIMV). - High-Frequency Ventilation (HFV): Uses rapid respiratory rates and very small tidal volumes to improve gas exchange and minimize lung injury.