An eSIM is a rewritable SIM card which is embedded in a mobile phone or other mobile device.
The e in eSIM stands for embedded. Unlike conventional SIM cards, eSIMs are not removable. Devices which include eSIMs can be used without inserting a SIM card. Instead, the SIM data is written to the eSIM to allow the device to connect to a mobile network. Instead of swapping a SIM card when you want to switch to a different mobile service provider, you add the data for that service provider to the eSIM.
Not all phones include an eSIM, and not all mobile service providers support eSIM functionality.
You can easily find out which Swiss mobile service providers support eSIM by selecting the eSIM filter in the mobile plan and prepaid offer comparison on moneyland.ch.
Interactive Swiss mobile plan comparison