In Australia where I'm from solid soap has practically been replaced by shower gel except for the older generations. I expected that this type of stuff and its name came from Euro-English but now I'm in Japan where English isn't anyone's first language and the liquid soap in the shower is labeled "body soap" which I assumed was a translation by someone unaware of our "shower gel" idiom.
To my surprise everybody else here thought "body soap" was the normal name for this stuff and didn't know the term "shower gel".
So my question is are the two regional synonyms? Is "shower gel" only used in Australia? Or are they slightly different products neither of which is as popular in all English-speaking markets?