Maybe you have already stumbled upon the term "eSIM" and wondered what such an eSIM actually is. As a further development of the classic SIM card, the eSIM is a chip permanently installed by the device manufacturer. The term eSIM as a short form for "embedded subscriber identity module" and describes a standardized procedure from the year 2015 for the authentication, storage and administration of user data for the respective network operator. With a size of approximately 6 x 5 mm, the eSIM simplifies card exchange and offers you the parallel use of two networks / two numbers in only one device.