Virgin sell both "proper broadband", with a co-ax cable, similar to (but not the same as) TV aerial cable coming into the house, or ADSL 2+, provided on an old-fashioned telephone line. It depends where you live, as co-ax cabling wasn't installed all over the country. It (co-ax) is usually in urban areas.
We have co-ax. It's very fast and reliable. Their phone service is pretty good too (we still have a telephone landline, although probably not for much longer). We're in a Bristol suburb: Virgin put their cable underground to the border of the property. To the building, if you haven't given them a duct, it'll be "whatever works", probably across a flowerbed or along a fence, with bright, light-green "ducting" (1.25" pipe really) where it's on the ground. They think this is cheaper than doing it properly -- if it breaks they simply come out and mend it.
The co-ax will (should!) be a complete run from the distribution point - a cabinet somewhere along the pavement - to your cable modem (Virgin "Super Hub"). Those domestic hubs have four gigabit network ports for cabled devices, and the latest ones have 802.11AC wireless (which in the real world is about half as fast as gigabit cable). Older ones, like ours, are 802.11N, which is nowhere near as quick.
There is a real difference between wireless and gigabit cable - wireless is _always_ a lot slower. But your overall speed will be limited by the slowest link in the chain. Depending on where you live, and who lives near you, this could be
- the device itself (phone, tablet, PC, TV or fridge),
- its connection (slow WiFi port),
- the hub or repeater (WiFi "range extenders" and "repeaters" usually kill performance,
- the cabling in the house (poorly made or damaged cables will be slower),
- Any bandwidth-hogs who live near you, as the bandwidth at the box on the pavement is shared out between those connected - when everyone wants to watch Clarkson on Amazon Prime at almost the same time, performance takes a big hit.
If performance is your aim, the various technologies score like this:
- ADSL and old 'phone modems - both obsolete
- ADSL 2+ - slowest (from almost everybody where there's nothing faster available locally, ALL OF IT being engineered by BT/Openreach)
- Virgin Co-Ax broadband - much faster and more reliable
- Fibre-optic to the pavement box - should be about the same as Virgin BB, or slightly faster*
- BT/Openreach (and anyone else's) Fibre to the Premises (FTTP) The fastest option available, only in certain areas.
Hope that helps. If you want proper HDTV over the internet, it's almost essential to have Virgin Co-Ax or better, and use good gigabit networking in the property (a physical gigabit cable) and NOT to try to connect your 4k TV over WiFi. Theoretically it works, but WiFi is slow and co-channel interference (from other people's systems) makes you hostage to fortune.
HTH,
E.
*you end up comparing apples with spanners: Sometimes Virgin have optical fibre up to the pavement box (and then co-ax cable); sometimes BT have big co-ax to the pavement box (and then optical fibre to the house), and sometimes it's legit to call physical copper "fibre" because of the way it's being used (although not in telecoms applications, I think, but certainly in datacentre storage, where 'fibre-channel' links to devices can be either copper, or optical). I've simplified it as much as I reasonably can.
[edited to remove ambiguity at the top - what was I thinking?!]