When a process is digital, it is a process where there are unities involved the relation between which is binary. This is the case of language, where the sequence between phonemes is what determines the meaning of a phrase. A phoneme is either a /b/ or it is not a /b/. “Bass” is not the same as “lace” which is different from “ace”. Needless to say, computers are essentially digital, since everything inside must be broken down into a stream of zeroes and ones. What is important to note about digital processes is that they are linear. Interpreting the meaning in a digital stream requires that we are able to perceive one unit at a time. Only one person can speak at a time, and though we are masters at processing simultaneous streams of phonemes, text and other binary information, while filling out the missing parts, and short term storing for later processing when under perceptual pressure, digital processes still remain linear and non-simultaneous.
In analogue processes, the relation between elements is gradient. Perceiving gesture is an analogue process, since it gives us information not only about is-it-a-smile or is-it-not-a-smile, but also about the width of the smile, the duration, its development over time. Analogue processes are perceived simultaneously. We take our surroundings in holistically, receiving sensorial information through all channels at the same time, as we are bathed in sounds, movements, colours, smells, etc. Analogue processes are context dependent. My perceiving of your smile as the happiest smile possible is only due to the fact that I know by experience how you as an individual smile in different contexts. And because I know that a minute ago you were sad. The same smile might be interpreted as a completely disinterested gesture, by a stranger seeing it on a photo on facebook.
Digital and analogue processes coexist, and when you engage in the digital process of forming sequences of phonemes, you inevitably supply it with prosodic, gestural and motoric ‘tracks’ of analogue information.