An eSIM is a convenient solution for accessing mobile data on demand, when you are overseas or are unable to access a physical SIM card for other reasons. With an eSIM, you can purchase a mobile data plan using an app after which you are sent a QR code that you scan to activate it on your phone.
An eSIM (embedded subscriber identity module) is a chip built into newer phones. It is used in addition the normal SIM card that every phone has and operates through software to deliver data service to your phone.
Since eSIMs are software-based instead of the service being hardwired into a SIM card, you can switch carriers or plans as often as you wish without having to wait for a physical SIM card. They are a particularly good option if you are doing a lot of travelling. An eSIM international data plan is relatively inexpensive, paid monthly and operates in multiple countries. It is much less expensive than signing up to a new provider in each country and operates on fast 4G networks.