The laptop AC adapter is the external power supply for your laptop computer. Because of the bulky adapter body between the laptop and the power cord, it's appropriately nicknamed the "power brick". Laptop users are often on the move, and as a result, a laptop power adapter can take a lot of abuse and will often need replacing.
It may also be a good idea to keep a spare laptop power cord around, either for emergencies...and convenience! Keep one at home, one in the office, and maybe a spare in your travel bag. You never know when you'll need that extra power!
AC adapters are typically designed for international inputs ranging from 100VAC to 240VAC, and can either run on 60hZ or 50hZ. Various power plug adapters are available to convert the standard US power cord to fit into international power sockets.
Click on the brand name below that matches your laptop: