It would be very unusual if the AC adapter (the "brick" that you plug in to the wall) is not a universal power supply. To check, read the fine print on it, and you will likely see that it works with 100-240V and 50-60Hz. If this is the case (almost a certainty), all you need is a plug adapter for the different countries that you visit.

For your Internet connection, you will find that both Ethernet and wireless connections are universal. If you are using a telephone line modem, you'll need a different type of connecting wire.

Doug, San Francisco