5.7Salesforce IDs

Salesforce assigns an Id to every record.

Example:

001xx000003DGbY

You do not generally create that yourself.

Objects have characteristic prefixes, but don't waste interview-study time memorizing prefixes.

What's important:

Salesforce Id
= Salesforce's internal identity

External ID
= business/source-system identity

Example:

Salesforce Account

Id:
001ABC...

External_Customer_ID__c:
CUST-81725

For integrations, both are useful for different reasons.