A laptop operates on **DC (Direct Current)** power, but the power that comes from a wall outlet is **AC (Alternating Current)**. Here's how the conversion happens:
1. **Wall Outlet Power (AC):** In most homes or offices, the power provided by outlets is AC, typically at 120V or 230V, depending on the country.
2. **Laptop Power Adapter:** The laptop's power adapter (or charger) is responsible for converting AC power from the outlet into DC power, which is what your laptop requires to function. The adapter does this through a built-in **rectifier** that transforms AC into the lower-voltage DC.
3. **Laptop’s Input (DC):** Once the AC power is converted by the adapter, the laptop receives the **DC** power, which is typically between 19-20V, depending on the model of the laptop. This DC power is used to charge the laptop's battery and run its internal circuits.
### In Summary:
- **Power Source (Wall Outlet):** AC (Alternating Current)
- **Power Adapter:** Converts AC to DC
- **Laptop Input:** DC (Direct Current)
So, while the electricity from the wall is AC, your laptop itself only uses DC.