cakeboy is slightly wrong.
A DVD usually has a TV tuner inside, which can be either analogue or digital (the same as Video recorders always had a TV tuner inside).
When you record on a VHS (or DVD) you are normally recording from the tuner inside the recorder itself.
So if the recorder only has an analogue tuner you can only record the 5 main channels, if it has a digital (freeview) tuner then you can record any digital channel.
So you need to buy a DVD recorder with a digital tuner inside.
You can plug a Scart cable into the back of a DVD recorder so it will record whatever is coming IN from that scart lead (which could be a Sky box for example). In that case you need to set your DVD recorder on the AV1 / AV2 or EXT1 / EXT2 channel