eSIM is the digital version of a physical SIM card. Quick to buy and easy to install. eSIM can be used in mobile phones, tablets, smart watches, etc. eSIM lets you change your carrier, data, or plan through software. On eSIM-compatible devices, you can go to the Settings menu and scan a photo of a QR code to activate or install the eSIM. You don't need to go to a store to purchase an eSIM and you don't need to insert the SIM card into your phone. With eSIM, everything can be done digitally online.