As an American, I grew up with ramen noodles, that is the very cheap wavy dried noodles one buys to eat, on a student's diet. Warm and filling, though honestly the nutritional content is quite suspect.
I had no idea that this dried out version has extremely little to do with the actual food in Japan. While even the term is somewhat confusing, the main thing is that ramen is traditionally a Chinese dish with many varieties, more similar to udon in Japan.
Japanese ramen is a Chinese noodle dish that has been further modified to suit Japanese tastes. Therefore, Japanese ramen is called "Japanese style ramen" in China.
In Japan, there are also a large number of varieties of ramen, but they generally have a wheat noodle with a firm texture (though that noodle may be thin or thick, and the firmness may be a choice of the diner.