How does EMT work?

Can you elaborate on how Emergency Medical Technicians (EMTs) work? I'm curious about the specific procedures they follow when responding to an emergency call, from the moment they arrive on the scene to transporting the patient to the hospital. What kind of training and certifications do they need to perform their duties effectively? Additionally, how do they collaborate with other emergency responders, such as paramedics and firefighters, to ensure the best possible outcome for the patient?