Most Contacted Domains Iphone Meaning Explained?

Oh my, this is quite confusing for me! Thank you both for explaining. So if I understand correctly, these “domains” are like little messages my phone sends out automatically, not necessarily websites my grandkids actually visited?

I do worry about what apps might be tracking them. Is there a simple way I can check which apps are being too nosy? The technical terms like “CDN” and “API calls” are a bit over my head. Also, should I be concerned if I see lots of unfamiliar names on that list, or is that pretty normal these days?

Any simple tips would be much appreciated! :folded_hands: