Help with Minecraft

[Ilovehatecleaning]

I've been on Google/MC and still lost so thought I'd ask people who no doubt have gone through this. I know I make it sound like an ordeal but it is to me!
My DC would like MC downloaded on laptop. Problem is, I also need to use the laptop so can they swap between using laptop and tablet or is it just for one device?
Also, how can they connect to other realms with their friends?
Thank you. Very simple explanations very much appreciated It's going to be a long summer

Please help 😫. I would be so grateful 😊

Accessing the same world ( single player) from different devices - no.
If they have been invited to a multiplayer server then they can access that world from different devices.
However, PC's run MC Java, mobile devices can't access Java.
Laptops / MacBooks can run MC Java but the above situation still applies for single player and multiplayer worlds.

does your DC have a gamertag? If s/he has, then they can access a realm from whatever device they are signed in on.
There’s a whole other can of worms in that worlds created on tablet minecraft (bedrock, free) MAY not necessarily be compatible with the paid-for minecraft on pc… (and vice versa)
You’re not the only one lost though; the interface of microsoft, minecraft, Google and, in our house, Xbox and epic games makes my head explode.