A BVM, or Bag Valve Mask, is a device used by Emergency Medical Technicians (EMTs) to provide artificial ventilation to patients. It is an important tool in emergency situations when a patient is not breathing adequately or has stopped breathing completely. The BVM is used to deliver oxygen into the patient's lungs by manually squeezing a bag connected to a face mask. This article explains the purpose and usage of the BVM in a simple manner for EMTs to understand.