What is the function of an External ID field in Salesforce?

Question

Salesforce Admin — Medium

What is the function of an External ID field in Salesforce?

Accepted Answer

External ID fields in Salesforce serve a specific purpose: they store identifiers from external systems, facilitating upsert operations and cross-object lookups during data imports. This enables seamless integration with external data sources. Incorrect options, such as auto-generating unique identifiers or preventing duplicate records, are not the primary function of External ID fields.