The term "social network" has a very clear, unambiguous meaning. However, this meaning has been lost through the workings of post-modern corruption, which leaves us under the imperative of tracing back the original sense... well, from its origins, by taking it apart piece by piece and then reconstructing it.
The first part, "social", is common to most European langauges and comes from the Latin "socialis", itself derived from "socius" and the suffix "-alis". In particular "socius" has retained its meaning in Romanian, in the word "soț" (feminine: "soață", or "soție"), which means "partner" in the particular sense of two people forming a sort of partnership, as well as the more general, albeit less common sense of two objects that are partnered together to form a pair of whatever sorts. The "-alis" suffix is added for augmentation, i.e. to denote more people that are considered under some form of partnership, as well as to adjectivize the noun, i.e. to denote something pertaining to the socius. Thus: we say that a particular thing is social whenever we take it in relation to (a) society, usually of living beings. For example, humans are social animals; people have a certain social status; living in a society determines one to develop a set of social skills; and so on and so forth.
The second part of our expression, "network", is an English word composed of: "net", a cognate of "knot", more generally, something bound together; and "work", generally (as well as in this case) meaning "something done". Thus "network" may be defined as: something done to bring a certain set of items together. In particular, nets evoke the image of the interwoven fabric used for example to catch fish, so more generally, a network is a set of interconnected things forming a certain sort of whole.
Inasmuch as "society" most commonly refers to the human kind, a "social" network is a set of interconnected humans, or otherwise work done to bring humans together, which in either case is somewhat of a pleonasm, since society already implies togetherness. Still, the so-called network, with the image of a mesh so deeply engendered into the English-speaking mind, brings forth a certain (usually complex) structure, whereas society isn't so specific. The social network is that group of people with which some particular person is actively connected, either directly or otherwise -- in other words, what some people would call a web of trust. One makes use of his network when, for example, trying to get ahold of an item that he otherwise couldn't, since he knows someone who knows someone who... you get the idea. Knowing someone, albeit not fashionable today, always was and will remain a thing.
Thusly proceeding, we can now say with certitude what social networks aren't. A social network is not technical nor technological by any means. It is not a platform and it is nothing so particular as a star topology -- the star topology is indeed a particular structure of networks (in general), but let us not confuse the two. What people nowadays call social networks are indeed networks, but there is nothing social about them; as there is nothing social about interconnected computers exchanging arbitrary data. For the same money, we could say that my blog is a social network with a number of nodes equal to one, but this doesn't make it more or less social than any other web site, certainly not in my absence. At most, that which is commonly called a "social network" is a facilitator for human -- but strictly for human interactions. If it detracts from that which makes one human, then it certainly isn't anything of the social sort.
Outside of this definition, the so-called "social network" is as much nonsense as that fabled "operating" system.
[...] than presented in this page, given that both the Hohenzollerns and the Romanovs were part of a network of wealthy and powerful families, while Alexander II was of Prussian descent on his mother's side, [...]