Writing is the act of recording language on a visual medium using a set of symbols. The symbols must be known to others, so that the text may be read. A text may also use other visual systems, such as illustrations and decorations. These are not called writing, but may help the message work. Usually, all educated people in a country use the same writing system to record the same language. To be able to read and write is to be literate. Writing differs from speech because the readers need not be present at the time. We can read writing from long ago, and from different parts of the world. Text stores and communicates knowledge. Writing is one of the greatest inventions of the human species. It was invented after people settled in towns, and after agriculture started. Writing dates from about 3,300BC, which is over 5000 years ago, in the Middle East. Writing today is usually on paper, though there are ways to print on almost any surface. Television and movie screens can also display writing, and so can computer screens. Many writing materials were invented, long before paper. Clay, papyrus, wood, slate and parchment (prepared animal...