What do you do online that might leave a digital footprint

Anything that you post online is part of your digital footprint. Social media is a big part of your digital footprint.

Freezing meltingand evaporation

An informal structure in a bureaucracy would be something like so-called "office politics". where there's a formal structure set up for the organization, but then an informal subculture as well that has a way of organizing the bureaucracy further. this can be positive because it sets up an added degree of organization, albeit informal, within the bureaucracy.