The modern Cylon is a biped robotic machine. They come in a variety of forms, with the Silver Centurion being the most common of all. The Cylons have their Empire, and within this Empire there coexists a few slave or member races. As such this Empire is referred to as either the Cylon Empire, or the Alliance.
Cylon society though, is very structured and ordered. Everything has its place, every Cylon their role. Cylons do have cities, military garrisons and most things that other races do. Just a different outlook.
Cylon society is also constantly evolving, unlike the Colonials. Their civilisation is constantly being built upon and upgraded whenever it needs to be. That does not mean to say that all aspects are advancing, nor that all changes are for the better. Militarily wise, it does not even mean that ship designs are constantly being churned out (indeed,the Baseship is, like the Battlestars, several hundred yahrens old in design), but when changes need to happen, they happen.
There is a second battleground for some Cylons. While the First and Silver Centurions have war as their battlefield, and the drones simply live to serve, for the citizens and the IL Series of Cylons, their primary battles are usually fought in the political arena. While Cylon does not have vast halls where Cylons can debate issues amongst themselves, every Cylon who is able, is constantly trying to get higher in favour with their superiors, and for the IL Series, their final aim is to be the next imperious Leader. A Cylon would never even think of allowing another Cylon to be harmed deliberately and in a physical manner - assassination and physical force against a fellow Cylon has never once happened in a millenia (save as a punishment), however they do not think twice of lying, slander, hording and with holding information if it would further their cause and they think they could get away with it. Cylons are ambitious, but at the same time this ambition must be held in check. Too ambitious Cylons are deemed unhealthy and they will more than likely be exiled rather than promoted. At the same time, a Cylon who is found to be deliberately with holding information will be deemed a criminal and punished accordingly. Thus a Cylon has to be devious, back stabbing and careful to walk the thin line between ambition and being a criminal. Some things a Cylon would not do - as well as violence - include blackmail and forgery. Instead, it is all about who you speak to and what you say, preferably before the other Cylon does.
Because every Cylon is self aware - despite their varying degrees of intelligence - there is always a Cylon wanting to get ahead of another. And crime against other Cylons does occur. Between Drones, Citizens and Centurions, crime is generally unheard off. However, amongst the IL Series, it is more common. However, crime does not exist in the usual sense. Cylons do not steal or do not murder their own. That would be pointless and a waste. However, they do vie for political status and additional rank within Cylon society, and this is where a Cylon commits the most crimes. Crimes are generally when a Cylon goes against the values of Cylon Society. This is very difficult to define exactly, but includes things like acting out of station, behaving in a un-Cylon fashion, and putting yourself ahead of the Empire and the like.
Punishments vary for these sorts of crimes. They range from Exile to a non-important Cylon world, loss of a brain (and thus reduce in rank and status), dismantlement, or art. Cylon art and poetry is a disciplinary measure for criminals. Cylon society has no artisans except for the criminal class.
Cylons are by no means infallible. Whilst the Colonials do not have the technological ability (or the inclination) to build them, Cylons can, and do malfunction. Damage to a Cylons head can render them prone to malfunction, and this can take the form of them losing their memory, following others as their leaders and simply running amok. Whether the Cylons repair or destroy their malfunctioning comrades is unknown. Another flaw, is that most large bases or ships control their Cylon warriors through a central control station. If this is knocked out, then the Cylons under the control of that station will cease to function. This is not universal though, and neither is it required for a Cylons operation. Nor will it apply to First Centurions, IL series or citizens, only warriors. The advantage of this, is that the Cylons controlled can be guided by the controlling influence and this means that they may have access to sensor data that would not normally be available to them.
Large amounts of humidity and water can cause the Cylons to malfunction.
Cylons like to do things properly, planning for every eventuality. Obviously, when dealing with humans, this is a very difficult thing to do, but one thing they do try and adhere to, is that there is no middle ground.
The Cylon symbol is two pentagons, one inside the other. The colour of the pentagons vary (in the series we see it either as a light blue or a light green), possibly due to differing units colours, Baseship command, or actual Cylon Commander.
The shape may or may not have any ramifications. Cylon Baseships have five landing bays, which can be linked to form a pentagon. We have not seen many other types of Cylon warship or architecture, so it is hard to determine if this has any other meaning or whether it is purely coincidental. It could be that the number 5 has special meaning for the Cylons. It could be that the pentagon is a very stylised version of a pentagon - after all, the Cylons were certainly influenced in some degree by Count Iblis, and I think we are led to believe that he is certainly evil - maybe even a fallen angel if you believe that the Ship of Lights is run by angels.