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 logographic writing 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.
A standard set of pictograms was defined in the international standard ISO 7001: Public Information Symbols. Another common set of pictograms are the laundry symbols used on clothing tags and chemical hazard labels.
Pictographic writing as a modernist poetic technique is credited to Ezra Pound, though French surrealists accurately credit the Pacific Northwest American Indians of Alaska who introduced writing, via totem poles, to North America.