Writing is a form of communication that uses visual symbols to convey information. The information shared by writing may be factual or emotional, concrete or abstract. Some of the earliest forms of writing were made by pressing a wedge-shaped tool, or stylus, into a tablet of wet clay. Since then, many other methods of writing have developed, including pencil or pen on paper or other materials such as vellum. In modern industrial societies, much writing is done in digital form, for instance on a computer or smartphone. Writing systems include alphabets, where letters are building blocks combined to form phonemes and words, and logographies, where characters represent morphemes and sometimes even whole words or concepts. A common English expression is to “get it in writing”, conveying the idea that having an agreement “in writing” is more binding and permanent than an oral agreement.