A SIM-card is a removable smart card that enables the subscriber to connect to a mobile network.
An eSIM is the combination of a remotely programmable chip in the phone or device (called an eUICC) and a digital profile, which contains information on subscriber identity and data for network authorisation. Together the eUICC (hardware) and digital eSIM profile (software) is the complete eSIM and works in exactly the same way as a traditional SIM-card.
The difference between the traditional SIM card and the eSIM is that it can be re-programmed or re-provisioned and can contain several digital eSIM profiles. This is not possible with a traditional SIM-card. Therefore, eSIM allows customers to change service providers without having to change the SIM-card.  
While removable SIM cards will continue to be the prevalent way of enabling mobile communications in our markets in the short to medium term, we expect eSIM technology, facilitated by the standardisation and specification work done by GSM Association (GSMA) and the European Telecommunications Standards Institute (ETSI), to become widespread over time due to its inherent benefits.
Examples of the benefits of eSIM are manifold. For device manufactures, eSIM will enable smaller devices and improved waterproofing, leave more room for other parts in the device, such as battery, and potentially lower production costs. For service providers, there will be opportunities to further digitalise distribution by simplifying the process for customers buying and activating connectivity for a wide range of devices. Telenor is also taking an active role in encouraging partner innovation built around eSIM solutions. For enterprises looking to utilise and/or sell Internet of Things (IoT) devices, the use of eSIM can reduce costs (no removable SIM cards required) and ease switching. Furthermore, IoT security and management will be an area where eSIM may contribute. Finally, consumers will be able to reap the benefits of all of the above through better devices, new services and greater flexibility in choice of connectivity provider. All in all, eSIM will contribute to societal welfare through increased service innovation and more connected devices.