The French word « document » is commonly used in two ways : first as the trace produced deliberately by a human activity, written down and materialized; second, as a source of information, of potential knowledge. In the digital age, the medium is becoming a complete hardware and software range and need a new definition. But the documents still have the double function of recording transactions and ideas, and offering answers to the readers' questions. However, the technology has to ensure that the content is fixed and reliable, and the information objects are maintained and preserved.