Early written symbols were based on pictograms (pictures which resemble what they signify) and ideograms (symbols which represent ideas). They were used by the ancient Chinese culture since around 5000 BC and began to develop into logographicwriting systems around 2000 BC. Pictograms are still in use as the main medium of written communication in some non-literate cultures in Africa, The Americas, and Oceania. Pictograms are often used as simple symbols by most contemporary cultures.
Pictograms can often transcend languages in that they can communicate to speakers of a number of tongues and language families equally effectively, even if the languages are cultures are completely different. This is why that road signs and similar pictographic material is often applied as a global standard expected to be understood by nearly all.
Pictograms remain in common use today, serving as signs or instructions. Because of their graphical nature and fairly realistic style, they are widely used to indicate public toilets, or places such as airports and train stations.
Reed, Ishmael (2003). From Totems to Hip-Hop: A Multicultural Anthology of Poetry Across the Americas, 1900-2002, Ishmael Reed, ed. ISBN 1-56025-458-0.