Help with Apple watch SE + Cellular

[smartiecake]

Help please
I am considering buying DH one of these for his birthday. He has an iPhone, so thinking it would connect to this.
However I don't have apple devices and have android. I don't know what I'm looking for and what is required.
Do i need a contract for the bloody watch? Or does it work against his iphone?
I'm not especially techy and am completely confused now I have read up on them.
Can anyone please let me know how these watches work and do I need to pay extra to make it work? If so I'm not getting him one.
Thanks

If he’ll always have his phone on him, you won’t need cellular.
But if he’s going to use the watch as a stand-alone, then yes you will. I think!
I have the SE, but generally have my phone with me so I didn’t get cellular.

Yeah as above, I use mine all the time, phone is generally somewhere in the house or my bag but attaches to the watch so I can call/text from that. But if he wants to go running without his phone for example, without cellular he wouldn't be able to call from it.

To be honest I imagine most people don't get cellular x

Oh and it doesn’t need to be cellular to track runs/walks etc. It can do that without the phone.

Ah ok, so is the cellular just for if you are away from the actual phone?
Can you still use the texts/calls on the non-cellular one?
Sorry if I'm being dim!

I think yes if you’re on wifi - but I’m not 100% sure!

It connects to the phone via bluetooth so it doesn't matter if you are on wifi or 3/4g.