Intelligent paper is an umbrella term encompassing most categories of papers, both digital and synthetic.

Nowadays most appear also have electronic functionality such as electronic paper (E-paper) for newspaper and E-books. In addition to that, smart papers, digital papers and synthetic electronic papers which have advanced properties.

Smart paper is made from wood pulp but able to performer more functions than just used for printing information.

Smart papers are capable of reacting to external forces such as external pressure, surrounding temperature or electromagnetic waves. Smart papers have been around for longer than we can realise. Some examples included carbon papers, litmus paper and thermal paper.

Currently, there are more advanced forms of smart paper which contain security features such as tags, avoiding theft, help maintain inventory/stock or even prevent counterfeiting.

Electronic papers which are known as E-paper is highly common. It is not made from wood pulp. Fibres and paper are not used as a substrate.

These are display devices which provide the appearance of ordinary ink on paper. Electronic papers displays are reflective rather than emissive.
In simple words, e-papers depend on external light sources instead of emitting their own light, such as LCD displays.

Smart electronic papers are synthetic papers and have electronic/conductive capabilities which are enabled through its inks or materials (fibres or polymers).

There are various types of digital papers. It can be used for digital printing, and include a wide range of printing papers. Digital papers can also be used with a digital pen to create handwritten digital documents and can be stored in electronic devices. Some digital papers have use magnets for storing digital information.