The electronic SIM card, or e-SIM, is the electronic version of the traditional SIM card used in mobile devices such as smartphones and tablets. The main difference between a regular SIM card and an e-SIM is that the e-SIM is not a physical card that can be inserted or removed from the device. The e-SIM is a digital version of the traditional SIM card.

The e-SIM is built directly into the device and does not require physical swapping of SIM cards when changing network operators. Users can easily switch network operators without the need for a physical SIM card replacement. Some devices with e-SIM may support multiple profiles, allowing the use of several phone numbers or networks simultaneously.

The e-SIM allows phone manufacturers to create more compact devices since they do not require SIM card slots. Users can easily select a network operator without the need to obtain and install a new SIM card.

The e-SIM is spreading in many countries and is supported by various mobile network operators and device manufacturers.