Can you please explain the 15 digit Id and 18 digit Id scenario in Salesforce?

Hi Prachi,

ID-15 are Case Sensitive
ID-18 are Case Safe

you can't have 2 separate records with the same ID-18

Inserting or updating records, the API accepts either the 15-character case-sensitive ID or the 18-character case-insensitive ID. When querying or searching records using the API, you must specify a value of “1” for the “useCaseSafeIDs” parameter to indicate that you want the API to return case-insensitive IDs. If you don’t specify the “useCaseSafeIDs” parameter, you automatically receive case-sensitive IDs. The API can return either a case-sensitive or a case-insensitive ID field value. The case-insensitive ID is identical to the 15-character case-sensitive ID, but with 3 extra characters appended to indicate the casing of each of the original 15 characters.