Anonymization is a process of irreversible data alteration so the data subject can no longer be identified. It is used as a method of protecting the data subject’s privacy and identity.
The biggest difference between anonymization and pseudonymization is that the pseudonymized data can be reversed using an additional set of information or encryption key, while anonymization is irreversible.
If the data is anonymized so the data subject is no longer identifiable (directly or indirectly), the GDPR does not classify it as personal data. This means anonymization can be used as an alternative to data deletion.