The definition of serial and parallel in electrical installations is interesting and I have also been confused recently. I work in IT and what I consider to be serial and parallel is very different in the IT world.
Fair enough - but, as you say, they are different worlds, and one has to use terminology appropriate to the world one is dealing with. It is perhaps not ideal that 'different worlds' often use the same words to use different things, but that's unfortunately how it is. If you asked suppliers of electrical items, tools, waste pipes or artificial limbs for a 'socket', you would be offered four totally different types of item.
As I'm sure you understand, the fundamental difference we are talking about is that, in the electrical case, one can wire things 'in series' such that the total voltage across the string of items is shared between each of the items, such that each 'sees' far less than the total voltage, but I can think of no direct equivalent of that in IT.
However, I would have thought that, even in IT, meanings of 'series' and 'parallel' similar to the electrical meanings would often be used. In terms of, say, network switches, would you not say that, in the following diagram, switches A, B, C and D were 'in series', whereas B, E and F were 'in parallel'?
I wonder what you feel about 'parallel processors' in a computer. I suspect that you would probably still call them 'parallel' even if they were largely physically 'wired in a daisy chain' with things like data buses going 'from one to another, down a string, wouldn't you?
Have a look at the following diagram which shows the difference between serial and parallel communication. .... You see the "daisy chaining" of the serial communication? Looks very similar to the way in which you would wire the downlights in "parallel"!
I wouldn't have said that was very comparable.
I agree that 'serial' and 'parallel' are totally different concepts (from the electrical one) in terms of
communication - although the latter are, I would have thought, largely a historical thing as far as IT is concerned. Originally, much of it was 'parallel' (e.g. Centronics printer ports), but that gave way to things like RS232 and eventually USB. However, those descriptors did not really refer to the method of wiring but, rather, to the way in which data was transmitted - either one bit at a time, 'serially' over time or by transmitted 7, 8 or whatever bits simultaneously ('in parallel'), through separate conductors. I suppose that's comparable with 4 cars wanting to travel down a road - they can either travel 'in parallel', each in their own lane of a 4-lane road, or 'in series', each behind one another on a single-lane road.
Serial communication is, I suspect, probably properly described as 'time-multiplexing', since groups of bits which eventually have to be separated and dealt with simultaneously (i.e. in parallel') are transmitted as a 'series' of discrete items transmitted separately over time. Put another way, the difference between serial and parallel
communication relates to whether several pieces of information (bits of data) are transmitted simultaneous along different communication links or 'serially' (over time) along a single link.
However, in electrical-speak, that would not be regarded as 'in parallel' since the 7/8/whatever conductors necessarily go to different places, rather than being 'joined together' (as in 'electrical parallel'). Within a computer, the data buses do, at least to some extent, represent 'parallel communication' (in the 'Centronics' sense of simultaneous transmission of different pieces on information along physically separate paths).
Just a few thoughts!
Kind Regards, John
