If you're using multiple eSIMs to stay connected in different countries on the same vacation, you'll be "switching" between different eSIMs depending on which country you're in at the moment.
For example, let's say you're spending a month going to London, then Paris for a few days, then Amsterdam for a few days, then back to London for a few days before you fly home.
You'll be in London at the beginning of the month AND at the end of the month, so you'll want to buy a 30-day U.K. eSIM data package.
You can purchase all three packages (and install all three eSIMs) before you leave on your trip. Your device can likely store 5-10 eSIMs at a time, but you'll only be using one at a time.
When you first arrive in the U.K., you will activate your U.K. data package and start the data flowing. Your eSIM U.K. will be "on" and set to be your phone's only source of data.
When you arrive in France, you'll turn your U.K. eSIM "off" and activate your France eSIM, setting it to be your phone's only source of data.
When you arrive in the Netherlands, you'll turn your France eSIM "off" and activate your Netherlands eSIM, setting it to be your phone's only source of data.
While you're in both France and the Netherlands, your 30-day U.K. eSIM data package will quietly tick down to its 30-day expiration but there won't be any data usage (since you won't be in the U.K. to connect to a U.K. network).
At the end of your trip, when you return to the U.K., you'll turn your Netherlands eSIM "off" and once again flip your U.K. eSIM back "on" and use it as your only source of data.
We hope this example helped explain how to hop between eSIMs on a multi-country vacation. Please reach out if we can help with further info!