PDF is a widely spread format for document sharing or publishing where others can open it. It allows you to include graphical elements, as well as tables, and plain text in it. One of the main features of the format is that it can be opened from any device.
PDF document is a 7-bit ASCII one, without those elements that can have binary content. The structure of the format consists of the following objects that may be either direct or indirect: boolean, names, strings, arrays, numbers, streams, dictionaries, and null.