Background: I'm in a legal academic discussion about the status of electronic 'goods' and whether they qualify as 'goods' in the same way a chair and a pen do. In this context (and specifically at the exact circumstance under discussion), it matters if electricity is 'tangible'. So far, most authors have blindly assumed electricity to be a flow of electrons, making a literal analogy with water, making statements such as:
information is stored in capacitors in the form of electrons. When a capacitor is filled more than 50% with electrons, it's considered to be 'on' (a bit with value '1').
the information represented by a certain current (or rather, a series of on/off currents) has mass, because it consists of the electrons that flow through the wire.
a virtual object is tangible because it exists in memory in the form of electrons that are there (or not) in a certain pattern.
Now I have a background in informatics but only a basic knowledge of electricity, and as good as none on the fundamental (physics) level. However I still feel this representation is wrong, and that you can't just say that information in a RAM chip has mass because it consists of electrons that are or are not in the capacitors on that chip. I have found hints in that direction on sites such as http://amasci.com/miscon/eleca.html#made, but I can't quite make out what 'electricity' is and how it relates to current and potential and other words that are used interchangeably in these discussions but which are, I think, different things.
So my questions are (all just different angles of looking at the same underlying concept):
What is 'electricity', really, on a fundamental level; but explained in terms a layman can understand? Is there an analogy with other things that is accurate, unlike the 'flowing water' analogy, which is sufficient for high school level but is a simplification? (at least, I think...)
Do 'electricity', an 'electrical current' and an 'electrical charge' have mass, apart from the object they are embodies in? Does the mass of a copper wire change when you put a current through it, because of the electrons coming in and going out?
How do electrons fit into this? Is electricity composed of a bunch of electrons that flow through a mass? I think not, reading the link I gave before, but I don't quite understand what their role is.
Most authors blindly assume that electricity is merely a flow of electrons through mass. In how far and under what assumptions is this correct?