I use the MagSafe Power Adapter in my Apple MacBook. They are great chargers, and the design, as with most Apple products, is pretty magnificent.

The cable connection is held in place by a magnet, making it safer if the wire is tugged and happens to come out of the laptop. At the main end of the adapter, there is a changeable end, so you can use the chargers in loads of different countries just by changing the adapter type.

The connector pins inside the charger have been designed so it can be inserted in either orientation. One problem here is, if the connector is facing one way, unfortunately it blocks some ports.
There is a small LED light on the connector, indicating the charge level in the laptop. If the light is green, the MacBook is charged. If the light is amber or red, the MacBook is charging.

Inside the connector end, there a 5 pins. 4 larger pins and 1 smaller pin, in the center. 2 pins inside the connector are grounded, preventing any dangerous situations for users. 2 pins in the connector carry the DC charge, and, the smaller pin, in the center controls the charge.

The MagSafe 60W charger comes in at around £60, which is quite expensive for what it is. You can get cheap, knock off versions of the MagSafe charger, but I doubt very much they work as well as the original Apple ones. Instead of wasting money on a cheaper version, that could possibly stop working after so long, I would go for the original Apple MagSafe charger.