Search can be like this: image search by image

Sometimes, you may encounter this situation: you see a picture online that seems familiar, but you just can't remember where you saw it, and you want to know more about the picture (for example, what's the name of the girl in the picture?). You have to ask on various forums or try using traditional image search engines, wracking your brain for some keywords, and finally get a bunch of irrelevant results. So, can you use an image to directly search for images?