A quick, but non academic search, shows no definition of this term. It is one that my colleagues and I have been using for a while. I hope to get a quick sketch of this term here, for a piece I am writing.
- Expressed in numerical form, especially for use by a computer. 
- Digital information is stored using a series of ones and zeros. Computers are digital machines because they can only read information as on or off — 1 or 0. This method of computation, also known as the binary system, may seem rather simplistic, but can be used to represent incredible amounts of data. 
- Traditionally, digital means the use of numbers and the term comes from digit, or finger. Today, digital is synonymous with computer. 
Two very interesting terms. One relating primarily to computers and electronic mediums. The other relating mostly to automobiles and their exhaust systems. The combination of the terms is designed to bring a similar thought to mind. One where the electronic medium produces its own exhaust system. The output is not air, gas, pollutants but instead photos, videos, blogs, and more. It is this representation that leads me to this definition…
- The output of human beings using the internet.
- The production of vast amounts of information in binary code, represented as words, texts, videos, photos and other mediums, expressed on computers and websites, and distributed across the internet.
- The individual representation of a person using the aggregate of their past interactions on the internet.