Previous answers to this question are rubbish, not seeming to understand that you can turn many smart TVs into a fully functioning video recorder by adding an hdd or USB memory stick.
However, trying to find documentation or information about this from Samsung manuals or technical support is very difficult, if not impossible.
If you've already purchased the TV, then try plugging your hdd into a USB socket marked hdd (this should power a 2.5 inch hdd without a separate power supply). Just press the record button on the remote. It may then test the device to see if it is compatible and offer to format it and off you go.
Some of their TVs won't work with an hdd over 500gb, if so you can partition the disc first. Might be worth doing anyway as 500gb will store a lot of programmes and you can use the rest of the drive for other files.
Best to use one partition to record TV as Samsung seems to record to the partition with most free space, meaning that Monday's episode is on "USB 1", but Tuesday's is on "USB 2", despite the fact that you've set one of them as the default.
Once recorded, these programmes can only be watched on that specific TV you can't play them on ANY other devices, unless you can break their encryption.