WHAT IS FIBRE OPTIC..?
Fibre Optic cable is a form of telecomunications wiring which is essentially made from thin fibres of high quality glass, it works by sending light signals through the cable at extremely high-speeds, Fibre Optic cable suffers less Attenuation (loss of signal over distance) unlike copper wiring and is immune to electro-magnetic interference.
This type of telecommunications cable is in use all over the world as a means to supply broadband and telecommunications signals around to different continents, countrys and end-users, as it has extremely low Attenuation this means very high broadband speeds can be delivered over greater distances, typically 100Mbps for end users but is capable of so much more.
some Fibre Optic links that run across ocean beds run at speeds upto 10Gbps (10,000Mbps) - as of April 2011 there is a new Fibre Optic cable being laid in the Pacific ocean by NEC that links Japan to the U.S. and other continets that has the ability to send and receive data at 100Gbps (it aso detects seismic tremors for earthquake detection).
Virgin Media supply broadband (up-to 100Mbps) because their networks consist of Fibre Optic and Co-axial copper cable and in some cases they get the Fibre Optic cable closer to your home than BT can with their telephone exchanges, but the main reason for their higher speeds is the fact they use much better quality co-axial copper cable for the 'last mile' and these Co-axial cable networks have boosters situated along them to keep them running fast.
I call this FTTH (Fibre-to-the-Hub) but some would disagree and state that as 'Fibre-to-the-Home' but thats already covered in FTTP so why have two names for it. This (a bit like BT's 21CN FTTC) is Fibre Optical cable to your local 'Hub' (in Cable telecommunications a 'Hub' is comparable to a Telephone Exchange where all the local connections meet the main network) and for the last section from the Hub to your home they use a high grade 'shielded' co-axial copper cable which does not lose signal as quick or as much as regular 'un-shielded' twisted pair copper cable used by BT (and in longer lengths) and as its shielded it is protected more from interference.
Virgin Media wrongly provide the 'illusion' that your getting Fibre Optic's into your home...when in reality your not, they (like BT) also use copper cable for the last mile - so with that in mind they are wrong to advertise that theyre 'Fibre' network is suprerior to other 'Copper' networks when in reality they too have copper as the last mile - just its better quality thats all, theoretically they still provide a faster service, but in practice it can be a coin toss due to them over-subscribing and under-supplyng in some areas.