Are you prepared to plug in?
Electrical systems differ around the world. Some use 50 hertz; some 60. Some use 110-120 volts; others 220-240. Some are on all the time, barring an ice storm or earthquake; some run a few hours a day. The plugs are also different so travelers with electrical appliances should ensure that they are adequately prepared. There are hundreds of different shaped adaptors available and each country will probably have their own version albeit doing generally the same job - enabeling users to either power up their electrical products or charge them.
Virtually all laptop computers (including those with internal power supplies) will handle a range of 100 to 240 volts and a frequency of 50 to 60Hz fine. In other words, you might not need a converter, transformer or adaptor; most power supplies have supported ranges printed directly on them (like on this image), so have a look. However, you will definitely need to make sure that you have the plug that matches the outlet for the country you are going to.
Once you know where you are going visit a local store to see if they carry the relevant adaptor for converting the electrical charge. You might have to go online to find a specialist supplier of a type of international electrical plug no easily available. Typical searches will take you to websites like Ebay or Amazon.