A power adapter, also known as an AC adapter or AC/DC adapter (also written as AC to DC adapter), is a device that converts AC power from a wall outlet into DC power suitable for powering electronic devices. These adapters are commonly used to power devices such as laptops, routers, modems, and other electronics that require a specific voltage and current.
Charger is a casual name for a power adapter, often used for phones, laptops, and other devices with batteries.