A converter is a device or tool that changes something from one form into another. The word comes from convert, which means to transform or change.

You encounter converters all the time without realizing it. That chunky box on your laptop's power cord is a converter: it changes the electricity from your wall outlet (which comes in one form) into the kind of electricity your computer can safely use. Without it, plugging your laptop directly into the wall could damage it.

Currency converters help travelers figure out how much money in one country is worth in another. If you're visiting Japan with American dollars, a currency converter tells you how many yen you'll get for each dollar.

In cars, a catalytic converter changes harmful exhaust gases into less dangerous ones before they leave the tailpipe. Video converters change files from one format to another, like turning a home video into a format that works on your phone.

Converters take something in, change its form or nature, and send out something different. They're like translators, but instead of changing languages, they change the form of energy, materials, or information into something more useful for a specific purpose.