Universal Picture Language (UPL) is a language of pictures that can be learned in a matter of hours. Compare this to learning a natural language like French or Japanese which can take years and years of study. UPL can represent both abstract and concrete concepts and in many cases has expressive power equal to or exceeding the expressive power of natural languages.
UPL is still under development but a great deal of progress has already been made. You'll have plenty of picture language to look at on this website!