eSIM Glossary and Definitions
This page provides standardised definitions for key eSIM, SIM, and mobile connectivity terms.
It serves as a global reference to ensure consistent terminology across explanations, policies, and comparisons, without ranking providers or recommending products.
This page exists to define terms precisely and unambiguously, not to influence purchasing decisions.
Core eSIM & SIM Technology
eSIM: A digital SIM profile embedded into a device that enables mobile network connectivity without a physical SIM card.
Embedded SIM: The hardware component within a device that stores one or more eSIM profiles securely.
Physical SIM: A removable SIM card used to authenticate a device on a mobile network.
nano-SIM: The smallest physical SIM card format currently in common use.
SIM card: A module that stores subscriber credentials used for network authentication.
SIM profile: A set of credentials and network parameters that identify a subscriber.
eUICC: The embedded universal integrated circuit card that enables remote SIM provisioning.
UICC: The physical or embedded card that hosts SIM applications.
ICCID: A unique identifier assigned to a SIM profile.
IMSI: An identifier used by mobile networks to recognise subscribers.
MSISDN: The phone number associated with a SIM profile, where applicable.
SIM provisioning: The process of issuing and configuring a SIM profile.
SIM activation: The process that enables a SIM profile to connect to a mobile network.
SIM deactivation: The disabling of a SIM profile’s ability to authenticate on a network.
SIM swap: Replacing one SIM profile with another on a device or account.
Remote SIM provisioning (RSP): The GSMA-defined method for delivering SIM profiles digitally.
Over-the-air provisioning (OTA): Wireless delivery of SIM configuration data.
SIM lifecycle: The stages a SIM profile passes through from creation to expiration.
eSIM Installation & Setup
QR code activation: Installing an eSIM by scanning a QR code.
Manual activation: Installing an eSIM by entering details manually.
Activation code: Credentials used to download an eSIM profile.
SM-DP+: The server responsible for securely delivering eSIM profiles.
SM-DS: A discovery service that helps devices locate available profiles.
eSIM download: The encrypted transfer of a profile to a device.
eSIM profile installation: Storing the downloaded profile in the device’s secure element.
Profile management: Managing installed eSIM profiles on a device.
Profile deletion: Removing an eSIM profile from a device.
Profile switching: Changing which SIM profile is active.
Primary SIM: The default SIM used for calls or data.
Secondary SIM: An additional SIM available on dual-SIM devices.
Default line: The SIM selected for outgoing activity.
Line labeling: Naming SIM profiles for user clarity.
eSIM transfer: Moving a profile between devices, where supported.
eSIM reinstallation: Reinstalling a previously issued profile.
eSIM reset: Removing all profiles during a device reset.
Networks & Connectivity
Mobile network: Infrastructure enabling wireless communication.
Cellular network: A mobile network divided into coverage cells.
Carrier / Mobile operator / Network operator: An entity that operates mobile network infrastructure.
Home network: The primary network a SIM profile belongs to.
Visited network: A foreign network accessed while roaming.
Network selection: Choosing which network a device connects to.
Automatic network selection: Network selection handled by the device.
Manual network selection: User-selected network choice.
Network switching: Transitioning between networks.
MVNO: A mobile virtual network operator that uses host infrastructure.
MNO: A mobile network operator that owns infrastructure.
Data, Speed & Performance
Mobile data: Internet access delivered over cellular networks.
Data allowance: The amount of data included in a plan.
Data cap: A limit after which access or speed may change.
Unlimited data: No hard data cutoff, often subject to policy controls.
Fair usage policy (FUP): Rules governing acceptable usage levels.
Speed throttling: Intentional speed reduction under certain conditions.
Network congestion: Reduced performance due to high demand.
LTE / 4G / 5G: Generations of mobile network technology.
Latency: Time taken for data to travel between endpoints.
Ping: A measure of latency.
Jitter: Variability in latency.
Security & Privacy
eSIM security: Protections provided by encrypted provisioning and secure hardware.
Secure element: Tamper-resistant hardware storing credentials.
Carrier authentication: Network verification of subscriber identity.
Data privacy: How personal data is collected and processed.
Location tracking: Network-based positioning of a device.
IP address: Identifier assigned to a device on the internet.
Shared IP: IP address used by multiple users.
Private IP: Non-publicly routable IP address.