eSIM (or embedded SIM) is a hardware-based SIM, which is attached permanently into a device. eSIM allows devices to be deployed anywhere with existing cellular coverage so that network providers can be added, updated or changed remotely. To use an eSIM, you have to buy an eSIM compatible device and use a carrier that provides that service. Then, you can install an eSIM profile that stores your user & network carrier information. Network operators can send out SIM profiles over-the-air to devices thus eliminating the need for end users to switch out the physical SIM in their device. An eSIM card is also smaller than a traditional SIM, which frees up more space in the design of devices. iSIM or (integrated SIM) takes all of the benefits of eSIM and embeds them into the device’s processor. While the eSIM is built into the device, it is still a separate processor within the phone. An iSIM builds the functionality of a SIM card into the device's sytem-on-chip (SoC) architecture without a separate processor. Since it does not require physical space for an eSIM chip or removable SIM card, the iSIM frees up more space in the design of devices. The iSIM also features additional authentication layers for enhanced security.