An AED is a portable medical device that checks a person’s heart rhythm and can deliver a controlled electric shock to restore a normal rhythm during sudden cardiac arrest. It is designed to be used by bystanders with minimal training, and it provides voice prompts and visual cues to guide the user through the steps. Key points about what an AED does:

• Analyzes the heart’s electrical activity to determine if a shock is needed.
• Delivers a shock if a shockable rhythm (such as ventricular fibrillation or pulseless ventricular tachycardia) is detected.
• Provides spoken and visual instructions to guide the rescuer through actions like applying pads, ensuring no one has contact with the person during shock delivery, and continuing CPR after the shock.
• Sometimes administers the shock automatically, while other models require a user-activated button.

Practical notes:

• AEDs are commonly located in public places (airports, schools, sports facilities) to enable rapid response in cardiac arrest cases.
• Modern units are designed to be safe and reliable; they will not deliver a shock unless it is appropriate.
• Training is recommended, though many people can use an AED effectively after basic instruction plus CPR.

If you’d like, I can tailor this explanation for a specific audience (e.g., lay bystanders, workplace responders, students) or provide a quick step-by- step usage guide.