If you're the curious sort, you're now probably wondering, well, why? What makes the money of one country more valuable than another? The probably-unsurprising answer to this question is: a whole lot of things.
For one thing, trade. In the modern world of complex, international trade, changing one currency for another is one way that stuff gets manufactured in one country and sold in another. If you have an economy that both imports a lot of stuff and is also very big, you might have a stable currency (and probably a highly traded currency too), but not necessarily a highly valuable one.
If, on the other hand, you are primarily an export economy, and you make (or dig up out of the ground) an especially valuable commodity that is hard to get elsewhere, you will very likely have both a stable and a valuable currency. That's why many of the strongest currencies in the world come from Gulf states whose economies are largely driven by oil exports.
To make matters even more complicated, currencies are also part of the world of international finance, and traded on the foreign exchange market. A currency that is in high demand will drive its value up, whereas a currency that has few interested buyers will see its relative value go down.