It just gives you service without the need for a physical sim. My eSIM is with Optus in Australia, and here is their explanation: https://www.optus.com.au/for-you/support/answer?id=20000
Thanks so much! I’m looking at Airalo which can be used in many countries. .Didn’t even know about this (and I’m reasonably tech savvy) until I watched a TikTok video today!
Some networks are doing a monthly roaming cost to allow you to use your UK contract in Europe. That might be worth checking out. EE charges £10 per month and your get to use all your UK minutes and data. Might save you the hassle of changing sim. Plus if you subtract what you’d be paying monthly for your Italian sim you might find your only paying a couple of quid on top of that to keep your UK number working.
You also need to check that your phone is not locked to a network or your Italian sim might not work anyway.