Recording TV Channels

I have just got a Sony smart TV using the inbuilt freeserve channels (KD43XF8796) and I am trying to get my head around its recording features. Sony recommend the use of a WD USB remote hard drive but I have looked at these units at Currys/PC World and they tell me that these units will only record the channel that you are watching which seems completely pointless.
Are they correct or is there more info out there?.

Regards

@johnlodge423 Have you already visited the Sony community and ask there?

https://us.community.sony.com/s/?language=en_US

I have a Sony 4K Smart TV too but haven’t looked at this since I have Spectrums set top box with DVR.

Ditto, get a cable TV box with built in DVR.